Elucidating the role of disorder and free-carrier recombination kinetics in CH3NH3PbI3 perovskite films.
Elucidating the role of disorder and free-carrier recombination kinetics in CH3NH3PbI3 perovskite films.
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DOI：
10.1038/ncomms8903
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发表时间：
2015-07-30
影响因子：
16.6
通讯作者：
Chia EE
中科院分区：
文献类型：
--
作者：
La-O-Vorakiat C;Salim T;Kadro J;Khuc MT;Haselsberger R;Cheng L;Xia H;Gurzadyan GG;Su H;Lam YM;Marcus RA;Michel-Beyerle ME;Chia EE
Apart from broadband absorption of solar radiation, the performance of photovoltaic devices is governed by the density and mobility of photogenerated charge carriers. The latter parameters indicate how many free carriers move away from their origin, and how fast, before loss mechanisms such as carrier recombination occur. However, only lower bounds of these parameters are usually obtained. Here we independently determine both density and mobility of charge carriers in a perovskite film by the use of time-resolved terahertz spectroscopy. Our data reveal the modification of the free carrier response by strong backscattering expected from these heavily disordered perovskite films. The results for different phases and different temperatures show a change of kinetics from two-body recombination at room temperature to three-body recombination at low temperatures. Our results suggest that perovskite-based solar cells can perform well even at low temperatures as long as the three-body recombination has not become predominant. In solar cells, the density and the mobility of charge carriers govern the device performance. Here the authors determine these quantities independently in perovskite films by time-resolved terahertz spectroscopy to study the influence of disorder and crystal structure as a function of temperature.
