第1章緒論1.1引言能源是人類賴以生存的基礎，也是社會可持續(xù)發(fā)展的重要動力。自工業(yè)革命以來，石油、煤炭等化石燃料成為了人類文明快速發(fā)展進程中最為重要的能源。然而，由于化石能源的不可再生且開發(fā)利用規(guī)模的不斷增加，化石能源資源供不應求，現(xiàn)有的能源利用和經(jīng)濟發(fā)展已然遇到瓶頸。此外，化石燃料的大規(guī)模開發(fā)利用也導致了溫室氣體的過量排放，引發(fā)了全球變暖、極端天氣、環(huán)境惡化等一系列重大環(huán)境問題ADDINEN.CITE<EndNote><Cite><Author>Li</Author><Year>2022</Year><RecNum>1</RecNum><DisplayText><styleface="superscript">[1]</style></DisplayText><record><rec-number>1</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710836974">1</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Li,Li</author><author>Lin,Jian</author><author>Wu,Nianyuan</author><author>Xie,Shan</author><author>Meng,Chao</author><author>Zheng,Yanan</author><author>Wang,Xiaonan</author><author>Zhao,Yingru</author></authors></contributors><titles><title>Reviewandoutlookontheinternationalrenewableenergydevelopment</title><secondary-title>EnergyandBuiltEnvironment</secondary-title></titles><periodical><full-title>EnergyandBuiltEnvironment</full-title></periodical><pages>139-157</pages><volume>3</volume><number>2</number><keywords><keyword>GlobalEnergyTransition</keyword><keyword>RenewableEnergy</keyword><keyword>EnergyRestructuring</keyword><keyword>EnergyPolicy</keyword></keywords><dates><year>2022</year><pub-dates><date>2022/04/01/</date></pub-dates></dates><isbn>2666-1233</isbn><urls><related-urls><url>/science/article/pii/S2666123320301148</url></related-urls></urls><electronic-resource-num>/10.1016/j.enbenv.2020.12.002</electronic-resource-num></record></Cite></EndNote>[1]。而隨著物聯(lián)網(wǎng)(IOT)時代的到來，大量獨立的微傳感器節(jié)點被應用于基礎設施領域，如工業(yè)、農(nóng)業(yè)以及許多其他領域。以化石能源為基礎的集中供能難以滿足其所需要的大規(guī)模分布式能源。深入開發(fā)具有環(huán)境友好和分布式特征的可持續(xù)能源，不僅有助于緩解資源短缺，還能有效減少碳排放。傳統(tǒng)的電磁發(fā)電機雖然發(fā)展完備技術成熟，但由于成本高、結構大的特點，顯然不適合分布式系統(tǒng)。因此，探索一種獨特的分布式能量收集技術，實現(xiàn)可再生能源有效收集迫在眉睫ADDINEN.CITE<EndNote><Cite><Author>Yang</Author><Year>2021</Year><RecNum>2</RecNum><DisplayText><styleface="superscript">[2]</style></DisplayText><record><rec-number>2</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710837985">2</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Yang,Ya</author><author>Wang,ZhongLin</author></authors></contributors><titles><title>Emergingnanogenerators:PoweringtheInternetofThingsbyhighentropyenergy</title><secondary-title>iScience</secondary-title></titles><periodical><full-title>iScience</full-title></periodical><pages>102358</pages><volume>24</volume><number>5</number><dates><year>2021</year><pub-dates><date>2021/05/21/</date></pub-dates></dates><isbn>2589-0042</isbn><urls><related-urls><url>/science/article/pii/S2589004221003266</url></related-urls></urls><electronic-resource-num>/10.1016/j.isci.2021.102358</electronic-resource-num></record></Cite></EndNote>[2]。在2012年，美國佐治亞理工學院王中林教授團隊發(fā)明了一種新型的能量收集技術，即摩擦納米發(fā)電機（TENG）ADDINEN.CITE<EndNote><Cite><Author>Wang</Author><Year>2019</Year><RecNum>7</RecNum><DisplayText><styleface="superscript">[3]</style></DisplayText><record><rec-number>7</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710839151">7</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Wang,ZhongLin</author><author>Wang,AureliaChi</author></authors></contributors><titles><title>Ontheoriginofcontact-electrification</title><secondary-title>MaterialsToday</secondary-title></titles><periodical><full-title>MaterialsToday</full-title></periodical><pages>34-51</pages><volume>30</volume><dates><year>2019</year><pub-dates><date>2019/11/01/</date></pub-dates></dates><isbn>1369-7021</isbn><urls><related-urls><url>/science/article/pii/S1369702119303700</url></related-urls></urls><electronic-resource-num>/10.1016/j.mattod.2019.05.016</electronic-resource-num></record></Cite></EndNote>[3]。憑借重量輕、體積小、制作簡單、綠色無污染且應用場景豐富等優(yōu)點，TENG被認為是21世紀高發(fā)展前景的能源技術。眾多研究表明，TENG可以將低頻環(huán)境能（包括雨水能、風能和水流能）轉化為電能，實現(xiàn)分布式設備供電或自供電系統(tǒng)集成ADDINEN.CITEADDINEN.CITE.DATA[4-6]，因而TENG在生物醫(yī)學、人工智能、人機交互等應用方面顯示出巨大的潛力。然而，傳統(tǒng)TENG只能輸出交流（AC）的電信號，無法直接滿足上述應用中微電子器件的直流（DC）需求ADDINEN.CITEADDINEN.CITE.DATA[7,8]。目前，較為常見的解決方案是將交流信號通過外部整流橋來轉換為直流信號，但這不可避免地造成額外的能量消耗和設計的復雜性，很大程度上限制了其在許多領域的應用，如柔性和兼容性電子器件ADDINEN.CITEADDINEN.CITE.DATA[9-12]。同時，由于材料固有摩擦電特性的極限和空氣擊穿的負面影響等等，傳統(tǒng)TENG的發(fā)展正面臨瓶頸。隨著對摩擦材料體系的進一步探索，人們發(fā)現(xiàn)半導體材料與金屬導體或半導體形成的摩擦界面能產(chǎn)生一種不同于傳統(tǒng)摩擦電效應的具有更高電荷密度的直流電信號。由于現(xiàn)象與光伏效應相似，因而將其命名為摩擦伏特效應ADDINEN.CITE<EndNote><Cite><Author>Liu</Author><Year>2018</Year><RecNum>14</RecNum><DisplayText><styleface="superscript">[13]</style></DisplayText><record><rec-number>14</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710839822">14</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Liu,Jun</author><author>Miao,Mengmeng</author><author>Jiang,Keren</author><author>Khan,Faheem</author><author>Goswami,Ankur</author><author>McGee,Ryan</author><author>Li,Zhi</author><author>Nguyen,Lan</author><author>Hu,Zhiyu</author><author>Lee,Jungchul</author><author>Cadien,Ken</author><author>Thundat,Thomas</author></authors></contributors><titles><title>Sustainedelectrontunnelingatunbiasedmetal-insulator-semiconductortriboelectriccontacts</title><secondary-title>NanoEnergy</secondary-title></titles><periodical><full-title>NanoEnergy</full-title></periodical><pages>320-326</pages><volume>48</volume><keywords><keyword>Energyharvesting</keyword><keyword>Triboelectricity</keyword><keyword>Tribo-tunneling</keyword><keyword>Direct-current</keyword><keyword>Metal-insulator-semiconductor</keyword></keywords><dates><year>2018</year><pub-dates><date>2018/06/01/</date></pub-dates></dates><isbn>2211-2855</isbn><urls><related-urls><url>/science/article/pii/S2211285518302052</url></related-urls></urls><electronic-resource-num>/10.1016/j.nanoen.2018.03.068</electronic-resource-num></record></Cite></EndNote>[13]。摩擦伏特效應的提出能以更簡易的結構和更高的電流密度實現(xiàn)直流摩擦納米發(fā)電機（DC-TENG）的制備，有望成為一種新型的高功率密度半導體能源技術。1.2摩擦伏特效應的形成機理2019年，王中林教授團隊利用開爾文力顯微鏡對摩擦起電現(xiàn)象進行了系統(tǒng)全面的研究，指出材料之間的電荷轉移是該現(xiàn)象產(chǎn)生的主要機制ADDINEN.CITE<EndNote><Cite><Author>Wang</Author><Year>2019</Year><RecNum>7</RecNum><DisplayText><styleface="superscript">[3]</style></DisplayText><record><rec-number>7</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710839151">7</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Wang,ZhongLin</author><author>Wang,AureliaChi</author></authors></contributors><titles><title>Ontheoriginofcontact-electrification</title><secondary-title>MaterialsToday</secondary-title></titles><periodical><full-title>MaterialsToday</full-title></periodical><pages>34-51</pages><volume>30</volume><dates><year>2019</year><pub-dates><date>2019/11/01/</date></pub-dates></dates><isbn>1369-7021</isbn><urls><related-urls><url>/science/article/pii/S1369702119303700</url></related-urls></urls><electronic-resource-num>/10.1016/j.mattod.2019.05.016</electronic-resource-num></record></Cite></EndNote>[3]。而傳統(tǒng)TENG耦合摩擦起電和靜電感應共同作用。通常不同的材料具有不同的電子親合能，把兩種材料碰觸到一起時，電子會從電子親合能低的材料轉移到電子親合能高的材料。更具體來說，當材料表面的原子相靠近，導致電子云重疊發(fā)生成鍵反應。當外力大到一定程度，形成強電子云重疊，使得兩種材料之間的勢壘降低，從而使電子從一個材料原子轉移到另一個材料原子。當材料彼此分離，轉移的電子會保留在材料表面，形成摩擦電荷。電荷由導線驅使流過外部電路，最終通過周期性的接觸和分離過程產(chǎn)生交流的電信號。不同于傳統(tǒng)的摩擦電效應，在滑動的半導體界面處能形成類似光生伏特效應即光伏效應的直流電輸出，命名為摩擦伏特效應。理解光伏過程對研究摩擦伏特機理具有重要意義。光伏效應是太陽能電池的理論基礎，實現(xiàn)光能到電能的轉化，是當今世界重要的清潔能源來源，普遍應用于全球各個角落ADDINEN.CITEADDINEN.CITE.DATA[14-16]。相較于摩擦伏特效應，經(jīng)過長達幾十年的研究發(fā)展，光伏效應的理論機制已經(jīng)較為明確，器件研究也十分成熟ADDINEN.CITEADDINEN.CITE.DATA[17-21]。不同半導體形成的異質結構成了太陽能電池的活性層，也就是光生伏特效應形成的地方，光伏效應原理如圖1-1所示ADDINEN.CITE<EndNote><Cite><Author>Liu</Author><Year>2018</Year><RecNum>14</RecNum><DisplayText><styleface="superscript">[13]</style></DisplayText><record><rec-number>14</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710839822">14</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Liu,Jun</author><author>Miao,Mengmeng</author><author>Jiang,Keren</author><author>Khan,Faheem</author><author>Goswami,Ankur</author><author>McGee,Ryan</author><author>Li,Zhi</author><author>Nguyen,Lan</author><author>Hu,Zhiyu</author><author>Lee,Jungchul</author><author>Cadien,Ken</author><author>Thundat,Thomas</author></authors></contributors><titles><title>Sustainedelectrontunnelingatunbiasedmetal-insulator-semiconductortriboelectriccontacts</title><secondary-title>NanoEnergy</secondary-title></titles><periodical><full-title>NanoEnergy</full-title></periodical><pages>320-326</pages><volume>48</volume><keywords><keyword>Energyharvesting</keyword><keyword>Triboelectricity</keyword><keyword>Tribo-tunneling</keyword><keyword>Direct-current</keyword><keyword>Metal-insulator-semiconductor</keyword></keywords><dates><year>2018</year><pub-dates><date>2018/06/01/</date></pub-dates></dates><isbn>2211-2855</isbn><urls><related-urls><url>/science/article/pii/S2211285518302052</url></related-urls></urls><electronic-resource-num>/10.1016/j.nanoen.2018.03.068</electronic-resource-num></record></Cite></EndNote>[22]。圖1-1a給出了P型和N型兩種半導體在接觸前的能帶結構。當兩者接觸時，N型半導體中的多數(shù)載流子（電子）會向P型半導體側擴散，空穴也會從P型半導體側向N型半導體側擴散，直到兩邊費米能級達到平衡。最終，P型半導體界面處累積電子而N型半導體界面累積空穴，形成內(nèi)建電場和耗盡區(qū)。當半導體異質結被太陽光照射，能量以光子形式進入異質結并激發(fā)出電子-空穴對（圖1-1b）。在內(nèi)建電場作用下，電子-空穴對進一步分離，電子向N型半導體側轉移，而空穴移向P型半導體側（圖1-1c）。最終，電荷通過外電路傳輸，形成光電流，實現(xiàn)光能向電能的轉換。圖SEQ圖表\*ARABIC1-1光伏效應的能帶圖：（a）P型半導體和N型半導體未接觸時；（b）PN結形成及電子空穴對的光激發(fā)；（c）內(nèi)建電場作用下電子空穴對的分離ADDINEN.CITE<EndNote><Cite><Author>Zheng</Author><Year>2020</Year><RecNum>44</RecNum><DisplayText><styleface="superscript">[22]</style></DisplayText><record><rec-number>44</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710842646">44</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Zheng,Mingli</author><author>Lin,Shiquan</author><author>Xu,Liang</author><author>Zhu,Laipan</author><author>Wang,ZhongLin</author></authors></contributors><titles><title>ScanningProbingoftheTribovoltaicEffectattheSlidingInterfaceofTwoSemiconductors</title><secondary-title>AdvancedMaterials</secondary-title></titles><periodical><full-title>AdvancedMaterials</full-title></periodical><pages>2000928</pages><volume>32</volume><number>21</number><keywords><keyword>conductiveatomicforcemicroscopy</keyword><keyword>contactelectrification</keyword><keyword>electrontransfer</keyword><keyword>semiconductors</keyword><keyword>tribovoltaiceffect</keyword></keywords><dates><year>2020</year><pub-dates><date>2020/05/01</date></pub-dates></dates><publisher>JohnWiley&Sons,Ltd</publisher><isbn>0935-9648</isbn><urls><related-urls><url>/10.1002/adma.202000928</url></related-urls></urls><electronic-resource-num>/10.1002/adma.202000928</electronic-resource-num><access-date>2024/03/19</access-date></record></Cite></EndNote>[22]。摩擦伏特效應與光伏效應類似，但不同的是，摩擦伏特電池將機械能轉化為電能，且機械能的注入來自摩擦。摩擦可以理解為當兩個接觸面之間發(fā)生滑動時因為相互作用而產(chǎn)生阻力。而幾乎所有的滑動界面的摩擦都會伴隨有能量的耗散ADDINEN.CITEADDINEN.CITE.DATA[19,21,23-25]?？梢哉J為，摩擦伏特效應將部分由于摩擦而耗散的能量轉化為了電能。宏觀摩擦理論中，摩擦會產(chǎn)生熱和界面形變，從而將損失的能量轉化為熱和變形能。有研究提出，摩擦伏特效應可以發(fā)生在超潤滑界面ADDINEN.CITE<EndNote><Cite><Author>Huang</Author><Year>2021</Year><RecNum>28</RecNum><DisplayText><styleface="superscript">[26]</style></DisplayText><record><rec-number>28</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710841097">28</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Huang,Xuanyu</author><author>Xiang,Xiaojian</author><author>Nie,Jinhui</author><author>Peng,Deli</author><author>Yang,Fuwei</author><author>Wu,Zhanghui</author><author>Jiang,Haiyang</author><author>Xu,Zhiping</author><author>Zheng,Quanshui</author></authors></contributors><titles><title>MicroscaleSchottkysuperlubricgeneratorwithhighdirect-currentdensityandultralonglife</title><secondary-title>NatureCommunications</secondary-title></titles><periodical><full-title>NatureCommunications</full-title></periodical><volume>12</volume><number>1</number><dates><year>2021</year></dates><publisher>SpringerScienceandBusinessMediaLLC</publisher><isbn>2041-1723</isbn><urls><related-urls><url>/10.1038/s41467-021-22371-1</url></related-urls></urls><electronic-resource-num>10.1038/s41467-021-22371-1</electronic-resource-num></record></Cite></EndNote>[26]，其中材料的變形是有限的。因此，材料的變形不太可能激發(fā)界面處的電子-空穴對，但摩擦導致的溫度升高對電子-空穴對激發(fā)作用還不能排除。想要更好地理解摩擦伏特效應的形成機理，需要引入對原子尺度上的摩擦能量耗散的討論。研究表明，就算是原子級平整的晶體表面摩擦也不會完全消失，有些時候摩擦甚至很顯著。于是各種微摩擦理論被提出，如“鵝卵石”模型ADDINEN.CITEADDINEN.CITE.DATA[27,28]、振蕩器模型ADDINEN.CITE<EndNote><Cite><Author>Xu</Author><Year>2007</Year><RecNum>32</RecNum><DisplayText><styleface="superscript">[29,30]</style></DisplayText><record><rec-number>32</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710841756">32</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Xu,Zhongming</author><author>Huang,Ping</author></authors></contributors><titles><title>Studyontheenergydissipationmechanismofatomic-scalefrictionwithcompositeoscillatormodel</title><secondary-title>Wear</secondary-title></titles><periodical><full-title>Wear</full-title></periodical><pages>972-977</pages><volume>262</volume><number>7</number><keywords><keyword>Friction</keyword><keyword>Energydissipationmechanism</keyword><keyword>Compositeoscillatormodel</keyword><keyword>IndependentOscillatormodel</keyword></keywords><dates><year>2007</year><pub-dates><date>2007/03/15/</date></pub-dates></dates><isbn>0043-1648</isbn><urls><related-urls><url>/science/article/pii/S0043164806003590</url></related-urls></urls><electronic-resource-num>/10.1016/j.wear.2006.10.002</electronic-resource-num></record></Cite><Cite><Author>Xu</Author><Year>2006</Year><RecNum>31</RecNum><record><rec-number>31</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710841755">31</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Xu,Z.M.</author><author>Huang,P.</author></authors></contributors><titles><title>Compositeoscillatormodelfortheenergydissipationmechanismoffriction</title><secondary-title>ActaPhysicaSinica-ChineseEdition-</secondary-title></titles><periodical><full-title>ActaPhysicaSinica-ChineseEdition-</full-title></periodical><pages>2427-2432</pages><volume>55</volume><dates><year>2006</year><pub-dates><date>05/01</date></pub-dates></dates><urls></urls></record></Cite></EndNote>[29,30]、聲子摩擦模型ADDINEN.CITE<EndNote><Cite><Author>Nakayama</Author><Year>1996</Year><RecNum>33</RecNum><DisplayText><styleface="superscript">[31]</style></DisplayText><record><rec-number>33</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710841788">33</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Nakayama,Keiji</author><author>Hashimoto,Hiroshi</author></authors></contributors><titles><title>Triboemission,tribochemicalreaction,andfrictionandwearinceramicsundervariousn-butanegaspressures</title><secondary-title>TribologyInternational</secondary-title></titles><periodical><full-title>TribologyInternational</full-title></periodical><pages>385-393</pages><volume>29</volume><number>5</number><keywords><keyword>triboemission</keyword><keyword>chargedparticle</keyword><keyword>electronion</keyword><keyword>photon</keyword><keyword>friction</keyword><keyword>wear</keyword><keyword>AlO</keyword><keyword>SiN</keyword><keyword>tribochemicalreaction</keyword><keyword>frictionpolymer</keyword></keywords><dates><year>1996</year><pub-dates><date>1996/08/01/</date></pub-dates></dates><isbn>0301-679X</isbn><urls><related-urls><url>/science/article/pii/0301679X9500077H</url></related-urls></urls><electronic-resource-num>/10.1016/0301-679X(95)00077-H</electronic-resource-num></record></Cite></EndNote>[31]和成鍵模型ADDINEN.CITEADDINEN.CITE.DATA[32-37]。在這些模型中，能量的耗散被解釋為與原子振動和化學鍵形成有很大關聯(lián)，其中化學鍵形成釋放的能量被認為可能大到足以實現(xiàn)電子-空穴對的激發(fā)。如圖1-2所示，在半導體硅的表面處部分硅原子的末端帶有一個-OH基團的懸空鍵ADDINEN.CITE<EndNote><Cite><Author>Tian</Author><Year>2019</Year><RecNum>36</RecNum><DisplayText><styleface="superscript">[36]</style></DisplayText><record><rec-number>36</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710841879">36</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Tian,Kaiwen</author><author>Li,Zhuohan</author><author>Gosvami,NityaN.</author><author>Goldsby,DavidL.</author><author>Szlufarska,Izabela</author><author>Carpick,RobertW.</author></authors></contributors><titles><title>MemoryDistanceforInterfacialChemicalBond-InducedFrictionattheNanoscale</title><secondary-title>ACSNano</secondary-title></titles><periodical><full-title>ACSNano</full-title></periodical><pages>7425-7434</pages><volume>13</volume><number>7</number><dates><year>2019</year><pub-dates><date>2019/07/23</date></pub-dates></dates><publisher>AmericanChemicalSociety</publisher><isbn>1936-0851</isbn><urls><related-urls><url>/10.1021/acsnano.8b09714</url></related-urls></urls><electronic-resource-num>10.1021/acsnano.8b09714</electronic-resource-num></record></Cite></EndNote>[36]。通過滑動，懸空的-OH基團與另一個表面上的另一個-OH基團發(fā)生硅醇縮合反應形成硅氧烷鍵（Si-O-Si），并釋放出一個H2O分子ADDINEN.CITE<EndNote><Cite><Author>Batteas</Author><Year>1999</Year><RecNum>40</RecNum><DisplayText><styleface="superscript">[32,34]</style></DisplayText><record><rec-number>40</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710842104">40</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Batteas,JamesD.</author><author>Quan,Xuhui</author><author>Weldon,MarcusK.</author></authors></contributors><titles><title>Adhesionandwearofcolloidalsilicaprobedbyforcemicroscopy</title><secondary-title>TribologyLetters</secondary-title></titles><periodical><full-title>TribologyLetters</full-title></periodical><pages>121-128</pages><volume>7</volume><number>2</number><dates><year>1999</year><pub-dates><date>1999/09/01</date></pub-dates></dates><isbn>1573-2711</isbn><urls><related-urls><url>/10.1023/A:1019125521376</url></related-urls></urls><electronic-resource-num>10.1023/A:1019125521376</electronic-resource-num></record></Cite><Cite><Author>Batteas</Author><Year>2003</Year><RecNum>39</RecNum><record><rec-number>39</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710842102">39</key></foreign-keys><ref-typename="BookSection">5</ref-type><contributors><authors><author>Batteas,James</author><author>Weldon,Marcus</author><author>Raghavachari,Krishnan</author></authors></contributors><titles><title>BondingandInterparticleInteractionsofSilicaNanoparticles</title></titles><pages>387-398</pages><dates><year>2003</year></dates><isbn>978-1-4613-5356-0</isbn><urls></urls><electronic-resource-num>10.1007/978-1-4615-1023-9_28</electronic-resource-num></record></Cite></EndNote>[32,34]?；瘜W鍵的形成伴隨著能量的釋放，這部分能量被視作是一個能量子，將其命名為“結合子”（Bindington）。于此同時，形成的硅氧烷鍵在滑動過程中被撕裂，伴隨著能量的吸收，而能量來源就是驅動滑動進行的機械能，從而造成機械能損失產(chǎn)生摩擦ADDINEN.CITE<EndNote><Cite><Author>Li</Author><Year>2014</Year><RecNum>41</RecNum><DisplayText><styleface="superscript">[38]</style></DisplayText><record><rec-number>41</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710842295">41</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Li,Ao</author><author>Liu,Yun</author><author>Szlufarska,Izabela</author></authors></contributors><titles><title>EffectsofInterfacialBondingonFrictionandWearatSilica/SilicaInterfaces</title><secondary-title>TribologyLetters</secondary-title></titles><periodical><full-title>TribologyLetters</full-title></periodical><pages>481-490</pages><volume>56</volume><number>3</number><dates><year>2014</year><pub-dates><date>2014/12/01</date></pub-dates></dates><isbn>1573-2711</isbn><urls><related-urls><url>/10.1007/s11249-014-0425-x</url></related-urls></urls><electronic-resource-num>10.1007/s11249-014-0425-x</electronic-resource-num></record></Cite></EndNote>[38]。隨著滑動的不斷進行，硅氧烷鍵不斷形成和斷裂，機械能以“結合子”的形式注入半導體界面。而“結合子”的能量值取決于化學鍵形成前后兩個成鍵原子電子軌道的能量差，最高可達到幾個電子伏特級別。在半導體界面，這些能量至少足以激發(fā)出一個電子-空穴對ADDINEN.CITEADDINEN.CITE.DATA[39,40]。圖1-SEQ圖表\*ARABIC2在滑動硅界面上發(fā)生的化學鍵形成斷裂反應示意圖基于以上討論，摩擦伏特效應的形成過程可以類比光伏效應進行描述。圖1-3a給出了兩種半導體接觸時的能帶圖。當接觸形成時，載流子發(fā)生擴散以平衡費米能級的差異，并形成內(nèi)建電場。當上下表面的半導體發(fā)生相對滑動時，兩個表面的原子距離非常近，表面懸空鍵相互影響，形成新的化學鍵，并釋放出“結合子”（圖1-3b）?！敖Y合子”以其能量激發(fā)界面上產(chǎn)生電子空穴對，就和入射光子在光伏效應的作用一樣（圖1-3c）。接著，電子空穴對在內(nèi)建電場的作用下分離，電子轉移到N型半導體一側，而空穴則轉移到P型半導體一側（圖1-3c），這樣在外電路中就產(chǎn)生了方向從P型半導體一側到N型半導體一側的直流摩擦電流。圖1-SEQ圖表\*ARABIC3摩擦伏特效應的能帶圖:（a）P型半導體和N型半導體形成接觸；（b）滑動過程中“結合子”激發(fā)電子空穴對;（c）內(nèi)建電場作用下電子空穴的分離和轉移。1.3摩擦伏特效應的種類和器件結構1.3.1不同界面處的摩擦伏特效應根據(jù)上述討論，摩擦伏特效應的產(chǎn)生條件可以總結為機械能以“結合子”形式注入，在摩擦界面處能激發(fā)電子空穴對，且存在內(nèi)建電場實現(xiàn)電荷分離。可以認為幾乎在所有摩擦界面上都普遍存在化學鍵的形成，這意味著摩擦伏特效應可以發(fā)生在任何形成內(nèi)建電場的滑動界面上。正如預期的那樣，最近的研究表明，在各種界面上都觀察到了摩擦伏特效應，包括金屬-半導體界面（肖特基結）ADDINEN.CITEADDINEN.CITE.DATA[22,41-46]，PN結ADDINEN.CITEADDINEN.CITE.DATA[22,47-49]，金屬-絕緣體-半導體界面ADDINEN.CITEADDINEN.CITE.DATA[13,41,50-52]，金屬-絕緣體-金屬界面ADDINEN.CITE<EndNote><Cite><Author>Benner</Author><Year>2022</Year><RecNum>63</RecNum><DisplayText><styleface="superscript">[50]</style></DisplayText><record><rec-number>63</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710843839">63</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Benner,Matthew</author><author>Yang,Ruizhe</author><author>Lin,Leqi</author><author>Liu,Maomao</author><author>Li,Huamin</author><author>Liu,Jun</author></authors></contributors><titles><title>MechanismofIn-PlaneandOut-of-PlaneTribovoltaicDirect-CurrentTransportwithaMetal/Oxide/MetalDynamicHeterojunction</title><secondary-title>ACSAppliedMaterials&Interfaces</secondary-title></titles><periodical><full-title>ACSAppliedMaterials&Interfaces</full-title></periodical><pages>2968-2978</pages><volume>14</volume><number>2</number><dates><year>2022</year><pub-dates><date>2022/01/19</date></pub-dates></dates><publisher>AmericanChemicalSociety</publisher><isbn>1944-8244</isbn><urls><related-urls><url>/10.1021/acsami.1c22438</url></related-urls></urls><electronic-resource-num>10.1021/acsami.1c22438</electronic-resource-num></record></Cite></EndNote>[50]，甚至液體-半導體界面ADDINEN.CITEADDINEN.CITE.DATA[39,40,53-55]。表1-1總結了摩擦伏特效應在不同界面下的輸出性能。表1-1不同界面處的摩擦伏特效應的輸出特性各種界面處的摩擦伏特效應的原理圖如圖1-4所示。摩擦伏特效應最早是在金屬-半導體界面上發(fā)現(xiàn)提出的ADDINEN.CITE<EndNote><Cite><Author>Wang</Author><Year>2019</Year><RecNum>7</RecNum><DisplayText><styleface="superscript">[3]</style></DisplayText><record><rec-number>7</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710839151">7</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Wang,ZhongLin</author><author>Wang,AureliaChi</author></authors></contributors><titles><title>Ontheoriginofcontact-electrification</title><secondary-title>MaterialsToday</secondary-title></titles><periodical><full-title>MaterialsToday</full-title></periodical><pages>34-51</pages><volume>30</volume><dates><year>2019</year><pub-dates><date>2019/11/01/</date></pub-dates></dates><isbn>1369-7021</isbn><urls><related-urls><url>/science/article/pii/S1369702119303700</url></related-urls></urls><electronic-resource-num>/10.1016/j.mattod.2019.05.016</electronic-resource-num></record></Cite></EndNote>[3]，后續(xù)也因此展開了眾多相關器件的研究。相較于半導體PN結界面，這些DC-TENG的一個優(yōu)點是具有較低的內(nèi)阻由于金屬本身較低的電阻。當金屬與半導體直接接觸時，將建立肖特基勢壘，而被激發(fā)的電子已被證明能夠穿過肖特基勢壘。電子有隧穿效應，當金屬和半導體之間有加入一層絕緣層，摩擦激發(fā)的電子也有機會能夠通過界面，但絕緣層厚度不能太厚，因為隧穿距離是有限的。根據(jù)目前的研究，金屬-絕緣體-半導體結構電阻較高，金屬-半導體界面處的摩擦電流通常大于金屬-絕緣體-半導體界面處的摩擦電流。然而，據(jù)報道，金屬-絕緣體-半導體滑動發(fā)生器的輸出電壓通常高于金屬-半導體滑動發(fā)生器的輸出電壓，這是由于在界面處勢壘高度的增強和熱電子的充放電ADDINEN.CITE<EndNote><Cite><Author>Lu</Author><Year>2019</Year><RecNum>55</RecNum><DisplayText><styleface="superscript">[41]</style></DisplayText><record><rec-number>55</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710843304">55</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Lu,Yanghua</author><author>Hao,Zhenzhen</author><author>Feng,Sirui</author><author>Shen,Runjiang</author><author>Yan,Yanfei</author><author>Lin,Shisheng</author></authors></contributors><titles><title>Direct-CurrentGeneratorBasedonDynamicPNJunctionswiththeDesignedVoltageOutput</title><secondary-title>iScience</secondary-title></titles><periodical><full-title>iScience</full-title></periodical><pages>58-69</pages><volume>22</volume><keywords><keyword>ElectricalEngineering</keyword><keyword>EnergyMaterials</keyword><keyword>MechanicalEngineering</keyword><keyword>Tribology</keyword></keywords><dates><year>2019</year><pub-dates><date>2019/12/20/</date></pub-dates></dates><isbn>2589-0042</isbn><urls><related-urls><url>/science/article/pii/S2589004219304547</url></related-urls></urls><electronic-resource-num>/10.1016/j.isci.2019.11.004</electronic-resource-num></record></Cite></EndNote>[41]。摩擦伏特效應高度依賴于兩個表面的相互作用，而絕緣體表面在某些特性方面如表面導熱系數(shù)等不同于導體表面，因此導體和某些絕緣體之間的相互作用可能比兩個導體之間相互作用更強，從而增強機械能注入激發(fā)更多電子并產(chǎn)生更高的摩擦電流/摩擦電壓。因此，在金屬-半導體界面引入薄絕緣層是優(yōu)化摩擦伏特器件的一個有效方法。在金屬-絕緣層-金屬結構中，量子隧穿效應、熱電子發(fā)射和陷阱態(tài)協(xié)助輸運的耦合作用決定了摩擦伏特電流的形成（圖1-4d）。其中，量子隧穿起主導作用在使用較薄絕緣體時，而隨著絕緣體層變厚時，主要電荷轉移機制轉變?yōu)闊犭娮影l(fā)射和陷阱態(tài)協(xié)助輸運。近年來，液-固TENG發(fā)明問世，液-固界面之間的接觸帶電也引起了研究人員的廣泛關注。與接觸起電一樣，摩擦伏特效應不僅發(fā)生在固-固界面，也可以發(fā)生在液-固界面。理解溶液-半導體界面處的摩擦伏特效應的一個關鍵點是，溶液可以被視作液態(tài)的半導體ADDINEN.CITEADDINEN.CITE.DATA[56-58]。當水溶液接觸固體半導體時，電子也將從一個表面擴散到另一個表面，以建立內(nèi)建電場，和在PN結中的情況相似。圖1-SEQ圖表\*ARABIC4不同界面處的摩擦伏特效應示意圖：（a）金屬-半導體接觸界面；（b）PN半導體異質結；（c）金屬-絕緣體-半導體結構；（d）金屬-絕緣體-金屬結構。1.3.2基于摩擦伏特效應的直流摩擦納米發(fā)電機器件結構根據(jù)不同的界面特性以及應用場景，直流摩擦伏特器件開發(fā)設計了多種結構，如圖1-5所示，有滑動結構ADDINEN.CITE<EndNote><Cite><Author>Xu</Author><Year>2019</Year><RecNum>83</RecNum><DisplayText><styleface="superscript">[42]</style></DisplayText><record><rec-number>83</rec-number><foreign-keys><keyapp="EN"db-id="p0t9x9zw5952wxefsfnx5swe0vrxtx95tvf2"timestamp="1710846573">83</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Xu,Ran</author><author>Zhang,Qing</author><author>Wang,JingYuan</author><author>Liu,Di</author><author>Wang,Jie</author><author>Wang,ZhongLin</author></authors></contributors><titles><title>Directcurrenttriboelectriccellbyslidingann-typesemiconductoronap-typesemiconductor</title><secondary-title>NanoEnergy</secondary-title></titles><periodical><full-title>NanoEnergy</full-title></periodical><pages>104185</pages><volume>66</volume><keywords><keyword>Directcurrentgenerators</keyword><keyword>Triboelectriccells</keyword><keyword>Doped