本文主要研究内容
作者居佃兴（2019）在《有铅—无铅卤化物钙钛矿晶体的生长与性能研究》一文中研究指出：有机-无机复合卤化物钙钛矿材料在太阳能电池、光电探测器以及LED等光电领域展现出无与伦比的应用潜力,引发全世界科研工作者的关注。然而,随着研究的深入,越来越多的问题出现在人们眼前,例如Pb的毒性,有机-无机复合钙钛矿材料及器件的稳定性,有机-无机复合钙钛矿材料的能带工程,以及尚不明确的晶体本征物理性质等,阻碍着该类材料的进一步商业化应用。因此,如何设计简单有效的方法调谐有机-无机复合宽带隙钙钛矿材料的光学带隙,减少Pb的毒性,改善其材料与器件的稳定性,探索新型无铅、高稳定性、窄带隙钙钛矿晶体材料,并深入系统地研究其本征物理性质是人们关注的重点。基于上述问题,本文设计生长了若干种新型有机-无机复合钙钛矿单晶材料,并以此为基础,通过气相诱导、掺杂等方式,调谐材料的光学带隙、降低Pb的含量及毒性,提高材料稳定性,以期拓宽其光电应用范围,深入研究其单晶结构及光、电、热学等本征物理性质,主要研究结果如下:1、设计利用甲胺气体诱导的方法调谐有机-无机复合Pb-基宽带隙钙钛矿单晶材料的光学带隙,在保留其单晶性的基础上改善其光电性能,并揭示其诱导机理。该种方法简单方便、快捷有效,且具有一定的普适性。以DMAPbI3为例,原位实时观察晶体转变过程,并系统研究转变前后晶体的光电性质。值得注意的是,经过甲胺气体诱导之后,DMAPbI3晶体的光学带隙由2.58 eV降低到1.53 eV,晶体的载流子迁移率提高2倍有余,其光响应开关比提高40余倍,光电性能大幅度提高。该诱导转变过程实际上是甲胺气体分子取代钙钛矿材料中有机基团的过程,随着诱导时间的延长,最终会形成MAPbI3材料,并保留原有形貌。进一步对碘铅丁胺(BA2PbI4)、碘铅己胺(HA2PbI4)、碘铅辛胺(OA2PbI4)以及碘铅胍(GAPbI3)等晶体材料进行甲胺气体诱导,发现与DMAPbI3相同的现象,光学带隙明显降低,表明该种诱导方法具有一定的普适性。2、基于Pb的毒性以及在混合卤素调节钙钛矿材料带隙时卤素离子迁移引起的相分离现象,我们设计生长Pb/Sn混金属离子的钙钛矿晶体,以研究其本征物理性质。其目的在于一方面减少Pb的毒性,另一方面在调谐带隙的前提下改善钙钛矿材料的相分离现象,提高材料稳定性。通过设计、探索以及优化晶体生长条件,获得不同Pb/Sn 比例下的大尺寸高质量的新型MAPbxSn1-xBr3钙钛矿晶体材料。所有MAPbxSn1-xBr晶体均属于 Cubic 晶系,Pm-3m空间群。另外,MAPbxSn11-xBr3材料展现出优异的半导体性质和较好的热力学稳定性。特别指出的是,通过改变Pb/Sn比例,不仅可显著调谐该类材料的光学带隙,最低可达到1.77 eV,带隙值明显低于MAPbBr3和MASnBr3,极大地扩展了该类材料的光伏响应范围,而且能够改善材料的稳定性,可在空气中稳定存在一个月以上,其稳定性显著优于MASnBr3。3、首次发现水相稳定的有机-无机复合Sn-基钙钛矿晶体DMASnI3具有晶体颜色自加深现象(带隙降低现象),并揭示了其变色机理。综合利用XRD、XPS、拉曼光谱以及第一性原理计算等表征手段揭示其变色机理为碘离子迁移生成的缺陷诱导晶体颜色加深现象。此外,通过UV-漫反射光谱、PL光谱、TRPL光谱、SCLC测试及霍尔效应等测试,系统研究了该材料的光电性能,结果表明该类材料具有优异的半导体性质。需要特别指出的是,DMASnI3晶体材料对H20展现出极好的稳定性,在水中浸泡16h后,其XRD图谱并无变化。基于其良好的水相稳定性,我们首次研究了该材料在去离子水中的H2产生性能,并成功实现产H2,极大的扩展了该材料的应用范围。4、设计利用Sn2+离子掺杂,改善Bi-基和Sb基等类钙钛矿材料的宽带隙问题,拓展其光电应用范围。掺杂之后,MA3Sb2I9和MA3Bi2I9等类钙钛矿材料的光学带隙显著降低。结合第一性原理计算,深入分析了 Sn2+离子掺杂之后的电子结构变化,揭示其带隙降低的原因。通过SCLC测试及霍尔效应等测试,系统研究了掺杂前后的电学性能。结果表明,Sn2+离子掺杂之后,MA3Sb2I9材料的载流子迁移率提高2倍。此外,Sn2+离子的掺入并未影响MA3Bi2I9、MA3Sb2I9等材料的稳定性,在空气中放置一个月,Sn-doped MA3Sb2I9和 Sn-doped MA3Bi2I9保持稳定。5、设计探索生长新型无铅、高稳定性、窄带隙的Te-基钙钛矿材料,并通过优化生长条件获得大尺寸单晶。利用X射线单晶衍射仪对一系列Te-基单晶材料进行单晶结构测试和解析,确定晶体结构。通过改变有机阳离子(MA+、FA+、BA+)以及卤素离子(Br-、I-),获得光学带隙可调的Te-基钙钛矿晶体材料(1.42-2.02 eV)。通过UV-漫反射光谱可知,MA2TeI6、FA2TeI6和BA2TeI6三种黑色晶体的光吸收截止边分别在843 nm、871 nm和812 nm,具有较大的光吸收范围,与MAPbI3相近。以MA2TeI6和MA2TeBr6为例,对其光电性能进行系统研究。MA2TeI6展现出较低的缺陷密度(～1010cm-3)以及较高的载流子迁移率(～65 cm2 V-1s-1),而MA2TeBr6单晶的最长荧光寿命可达到5958 ns,其对应的载流子扩散长度高达38 μm,在叠层太阳能电池等领域展现出潜在的应用价值。此外,该类材料具有优异的稳定性,可在空气中放置两个月而不引起变化。Te-基钙钛矿材料具有较窄的光学带隙和较好的稳定性,在光电领域具有潜在的应用优势。
Abstract
you ji -mo ji fu ge lu hua wu gai tai kuang cai liao zai tai yang neng dian chi 、guang dian tan ce qi yi ji LEDdeng guang dian ling yu zhan xian chu mo yu lun bi de ying yong qian li ,yin fa quan shi jie ke yan gong zuo zhe de guan zhu 。ran er ,sui zhao yan jiu de shen ru ,yue lai yue duo de wen ti chu xian zai ren men yan qian ,li ru Pbde du xing ,you ji -mo ji fu ge gai tai kuang cai liao ji qi jian de wen ding xing ,you ji -mo ji fu ge gai tai kuang cai liao de neng dai gong cheng ,yi ji shang bu ming que de jing ti ben zheng wu li xing zhi deng ,zu ai zhao gai lei cai liao de jin yi bu shang ye hua ying yong 。yin ci ,ru he she ji jian chan you xiao de fang fa diao xie you ji -mo ji fu ge kuan dai xi gai tai kuang cai liao de guang xue dai xi ,jian shao Pbde du xing ,gai shan ji cai liao yu qi jian de wen ding xing ,tan suo xin xing mo qian 、gao wen ding xing 、zhai dai xi gai tai kuang jing ti cai liao ,bing shen ru ji tong de yan jiu ji ben zheng wu li xing zhi shi ren men guan zhu de chong dian 。ji yu shang shu wen ti ,ben wen she ji sheng chang le re gan chong xin xing you ji -mo ji fu ge gai tai kuang chan jing cai liao ,bing yi ci wei ji chu ,tong guo qi xiang you dao 、can za deng fang shi ,diao xie cai liao de guang xue dai xi 、jiang di Pbde han liang ji du xing ,di gao cai liao wen ding xing ,yi ji ta kuan ji guang dian ying yong fan wei ,shen ru yan jiu ji chan jing jie gou ji guang 、dian 、re xue deng ben zheng wu li xing zhi ,zhu yao yan jiu jie guo ru xia :1、she ji li yong jia an qi ti you dao de fang fa diao xie you ji -mo ji fu ge Pb-ji kuan dai xi gai tai kuang chan jing cai liao de guang xue dai xi ,zai bao liu ji chan jing xing de ji chu shang gai shan ji guang dian xing neng ,bing jie shi ji you dao ji li 。gai chong fang fa jian chan fang bian 、kuai jie you xiao ,ju ju you yi ding de pu kuo xing 。yi DMAPbI3wei li ,yuan wei shi shi guan cha jing ti zhuai bian guo cheng ,bing ji tong yan jiu zhuai bian qian hou jing ti de guang dian xing zhi 。zhi de zhu yi de shi ,jing guo jia an qi ti you dao zhi hou ,DMAPbI3jing ti de guang xue dai xi you 2.58 eVjiang di dao 1.53 eV,jing ti de zai liu zi qian yi lv di gao 2bei you yu ,ji guang xiang ying kai guan bi di gao 40yu bei ,guang dian xing neng da fu du di gao 。gai you dao zhuai bian guo cheng shi ji shang shi jia an qi ti fen zi qu dai gai tai kuang cai liao zhong you ji ji tuan de guo cheng ,sui zhao you dao shi jian de yan chang ,zui zhong hui xing cheng MAPbI3cai liao ,bing bao liu yuan you xing mao 。jin yi bu dui dian qian ding an (BA2PbI4)、dian qian ji an (HA2PbI4)、dian qian xin an (OA2PbI4)yi ji dian qian gua (GAPbI3)deng jing ti cai liao jin hang jia an qi ti you dao ,fa xian yu DMAPbI3xiang tong de xian xiang ,guang xue dai xi ming xian jiang di ,biao ming gai chong you dao fang fa ju you yi ding de pu kuo xing 。2、ji yu Pbde du xing yi ji zai hun ge lu su diao jie gai tai kuang cai liao dai xi shi lu su li zi qian yi yin qi de xiang fen li xian xiang ,wo men she ji sheng chang Pb/Snhun jin shu li zi de gai tai kuang jing ti ,yi yan jiu ji ben zheng wu li xing zhi 。ji mu de zai yu yi fang mian jian shao Pbde du xing ,ling yi fang mian zai diao xie dai xi de qian di xia gai shan gai tai kuang cai liao de xiang fen li xian xiang ,di gao cai liao wen ding xing 。tong guo she ji 、tan suo yi ji you hua jing ti sheng chang tiao jian ,huo de bu tong Pb/Sn bi li xia de da che cun gao zhi liang de xin xing MAPbxSn1-xBr3gai tai kuang jing ti cai liao 。suo you MAPbxSn1-xBrjing ti jun shu yu Cubic jing ji ,Pm-3mkong jian qun 。ling wai ,MAPbxSn11-xBr3cai liao zhan xian chu you yi de ban dao ti xing zhi he jiao hao de re li xue wen ding xing 。te bie zhi chu de shi ,tong guo gai bian Pb/Snbi li ,bu jin ke xian zhe diao xie gai lei cai liao de guang xue dai xi ,zui di ke da dao 1.77 eV,dai xi zhi ming xian di yu MAPbBr3he MASnBr3,ji da de kuo zhan le gai lei cai liao de guang fu xiang ying fan wei ,er ju neng gou gai shan cai liao de wen ding xing ,ke zai kong qi zhong wen ding cun zai yi ge yue yi shang ,ji wen ding xing xian zhe you yu MASnBr3。3、shou ci fa xian shui xiang wen ding de you ji -mo ji fu ge Sn-ji gai tai kuang jing ti DMASnI3ju you jing ti yan se zi jia shen xian xiang (dai xi jiang di xian xiang ),bing jie shi le ji bian se ji li 。zeng ge li yong XRD、XPS、la man guang pu yi ji di yi xing yuan li ji suan deng biao zheng shou duan jie shi ji bian se ji li wei dian li zi qian yi sheng cheng de que xian you dao jing ti yan se jia shen xian xiang 。ci wai ,tong guo UV-man fan she guang pu 、PLguang pu 、TRPLguang pu 、SCLCce shi ji huo er xiao ying deng ce shi ,ji tong yan jiu le gai cai liao de guang dian xing neng ,jie guo biao ming gai lei cai liao ju you you yi de ban dao ti xing zhi 。xu yao te bie zhi chu de shi ,DMASnI3jing ti cai liao dui H20zhan xian chu ji hao de wen ding xing ,zai shui zhong jin pao 16hhou ,ji XRDtu pu bing mo bian hua 。ji yu ji liang hao de shui xiang wen ding xing ,wo men shou ci yan jiu le gai cai liao zai qu li zi shui zhong de H2chan sheng xing neng ,bing cheng gong shi xian chan H2,ji da de kuo zhan le gai cai liao de ying yong fan wei 。4、she ji li yong Sn2+li zi can za ,gai shan Bi-ji he Sbji deng lei gai tai kuang cai liao de kuan dai xi wen ti ,ta zhan ji guang dian ying yong fan wei 。can za zhi hou ,MA3Sb2I9he MA3Bi2I9deng lei gai tai kuang cai liao de guang xue dai xi xian zhe jiang di 。jie ge di yi xing yuan li ji suan ,shen ru fen xi le Sn2+li zi can za zhi hou de dian zi jie gou bian hua ,jie shi ji dai xi jiang di de yuan yin 。tong guo SCLCce shi ji huo er xiao ying deng ce shi ,ji tong yan jiu le can za qian hou de dian xue xing neng 。jie guo biao ming ,Sn2+li zi can za zhi hou ,MA3Sb2I9cai liao de zai liu zi qian yi lv di gao 2bei 。ci wai ,Sn2+li zi de can ru bing wei ying xiang MA3Bi2I9、MA3Sb2I9deng cai liao de wen ding xing ,zai kong qi zhong fang zhi yi ge yue ,Sn-doped MA3Sb2I9he Sn-doped MA3Bi2I9bao chi wen ding 。5、she ji tan suo sheng chang xin xing mo qian 、gao wen ding xing 、zhai dai xi de Te-ji gai tai kuang cai liao ,bing tong guo you hua sheng chang tiao jian huo de da che cun chan jing 。li yong Xshe xian chan jing yan she yi dui yi ji lie Te-ji chan jing cai liao jin hang chan jing jie gou ce shi he jie xi ,que ding jing ti jie gou 。tong guo gai bian you ji yang li zi (MA+、FA+、BA+)yi ji lu su li zi (Br-、I-),huo de guang xue dai xi ke diao de Te-ji gai tai kuang jing ti cai liao (1.42-2.02 eV)。tong guo UV-man fan she guang pu ke zhi ,MA2TeI6、FA2TeI6he BA2TeI6san chong hei se jing ti de guang xi shou jie zhi bian fen bie zai 843 nm、871 nmhe 812 nm,ju you jiao da de guang xi shou fan wei ,yu MAPbI3xiang jin 。yi MA2TeI6he MA2TeBr6wei li ,dui ji guang dian xing neng jin hang ji tong yan jiu 。MA2TeI6zhan xian chu jiao di de que xian mi du (～1010cm-3)yi ji jiao gao de zai liu zi qian yi lv (～65 cm2 V-1s-1),er MA2TeBr6chan jing de zui chang ying guang shou ming ke da dao 5958 ns,ji dui ying de zai liu zi kuo san chang du gao da 38 μm,zai die ceng tai yang neng dian chi deng ling yu zhan xian chu qian zai de ying yong jia zhi 。ci wai ,gai lei cai liao ju you you yi de wen ding xing ,ke zai kong qi zhong fang zhi liang ge yue er bu yin qi bian hua 。Te-ji gai tai kuang cai liao ju you jiao zhai de guang xue dai xi he jiao hao de wen ding xing ,zai guang dian ling yu ju you qian zai de ying yong you shi 。
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标签：晶体生长论文; 单晶结构论文; 光电性质论文; 稳定性论文; 山东大学2019-07-16论文;