不同取代基之肼類添加劑對有機無機錫鉛鈣鈦礦 太陽能電池元件效能之研究

Abstract

有機無機錫鉛混合型鈣鈦礦太陽能電池相較於目前主流的鉛基鈣鈦礦太陽能電池更為環保，在有機無機錫鉛混合型鈣鈦礦太陽能電池系統中，以芳香肼類化合物作為添加劑有助於提升電池穩定性，原因為芳香結構中推電子的特性，提升鄰近肼基抑制錫氧化的能力。因此本研究探討以下四種不同推電子取代基的芳香肼類化合物 phenylhydrazine hydrochloride (PH•HCl)、o-tolylhydrazine hydrochloride (OTH•HCl)、p-tolylhydrazine hydrochloride (PTH•HCl) 和1-naphthalenyl hydrazine hydrochloride (NH•HCl) 來對於錫鉛混合型鈣鈦礦太陽能電池的影響。其中以不含取代基之芳香肼類化合物PH•HCl作為基準，跟PHHCl相比之下，另外三種肼類化合物對於錫鉛混合型太陽能電池的穩定性均顯著提高。在元件穩定性方面: NH•HCl > OTH•HCl ~ PTH•HCl，其中NH•HCl使元件的壽命延長將近100%。除了穩定性的提升之外，薄膜的晶粒尺寸也有所增加，且能有效鈍化光自發光淬滅所造成的缺陷，也提高鈣鈦礦太陽能電池元件的複合電阻與載流子遷移率，進而使最高的光電轉換率提高10%，本研究的發現將為應用於錫鉛混合型與以錫為基底的鈣鈦礦太陽能電池之肼類添加劑有極大的幫助。

Aromatic hydrazine compounds have been shown to be effective stability-enhancing additives to Pb-Sn organic-inorganic halide perovskite solar cells (PSC)—a more eco-friendly alternative to the mainstream Pb-based PSC technology—owing to the electron-donating nature of the aromatic structure, which enhances the neighboring hydrazine group’s ability to suppress degradations Pb-Sn perovskites via oxidation of Sn2+. Aiming to advance this concept further, this study examined four aromatic hydrazine compounds with various electron-donating substituents as additives to Pb-Sn PSC devices, including phenylhydrazine hydrochloride (PH•HCl), o-tolylhydrazine hydrochloride (OTH•HCl), p-tolylhydrazine hydrochloride (PTH•HCl), and 1-naphthalenyl hydrazine hydrochloride (NH•HCl). Compared to PH•HCl, which has a non-substituted phenyl group and was used as a benchmark, the three other electron-donating-group-substituted hydrazines all showed greater enhancements in the stability of PSC devices, validating the premise of this work. The levels of stability enhancement yielded by the three substituted hydrazines followed the strength of their electron-donating substituents, i.e. NH•HCl > OTH•HCl ~ PTH•HCl, with NH•HCl extending the device lifetime by > 100%. In addition to stability enhancements, the three substituted hydrazines increased the crystal grain size in the Pb-Sn perovskite film, passivated photoluminescence-quenching defects therein, and increased recombination resistance and charge-carrier mobility through the PSC device, resulting in a maximal enhancement of 10% in power conversion efficiency. The findings of this work will offer guidance to designing and selecting hydrazine-type additives for Pb-Sn and Sn-based PSCs.