Employing time-resolved terahertz spectroscopy to analyze carrier dynamics in thin-film Cu2ZnSn(S,Se)4 absorber layers
Employing time-resolved terahertz spectroscopy to analyze carrier dynamics in thin-film Cu2ZnSn(S,Se)4 absorber layers
复制标题
采用时间分辨太赫兹光谱分析薄膜 Cu2ZnSn(S,Se)4 吸收层中的载流子动力学
DOI：
10.1063/1.4884817
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发表时间：
2014
影响因子：
4
通讯作者：
J. B. Baxter
中科院分区：
文献类型：
--
作者：
G. Guglietta;K. Choudhury;J. Caspar;J. B. Baxter
我们报告的时间分辨太赫兹光谱（TRTS）的应用程序来测量光激发载流子的寿命和迁移率，并确定复合机制的Cu 2 ZnSn（S，Se）4（CZTSSe）的薄膜制造的油墨。超快时间分辨率允许跟踪载流子密度的演变，以确定复合速率和机制。通过改变光激发波长和能量密度来操纵载流子生成曲线，以区分表面、肖克利-里德-霍尔（SRH）、辐射和俄歇复合机制并确定速率常数。表面复合和SRH复合是空气/CZTSSe/SiO2/Si薄膜叠层的主要机制。扩散到空气-CZTSSe界面，然后在界面处复合，发生在100皮秒的量级，而SRH复合寿命为1-2纳秒。TRTS测量可以提供信息，是传统的时间分辨光致发光测量的补充，并可以指导设计高效的薄膜光致发光。
We report the application of time-resolved terahertz spectroscopy (TRTS) to measure photoexcited carrier lifetimes and mobility, and to determine recombination mechanisms in Cu2ZnSn(S,Se)4 (CZTSSe) thin films fabricated from nanocrystal inks. Ultrafast time resolution permits tracking the evolution of carrier density to determine recombination rates and mechanisms. The carrier generation profile was manipulated by varying the photoexcitation wavelength and fluence to distinguish between surface, Shockley-Read-Hall (SRH), radiative, and Auger recombination mechanisms and determine rate constants. Surface and SRH recombination are the dominant mechanisms for the air/CZTSSe/SiO2/Si film stack. Diffusion to, and then recombination at, the air-CZTSSe interface occurred on the order of 100 picoseconds, while SRH recombination lifetimes were 1–2 nanoseconds. TRTS measurements can provide information that is complementary to conventional time-resolved photoluminescence measurements and can direct the design of efficient thin film photovoltaics.