捷克先令
光致发光
光电流
带隙
材料科学
谱线
锌黄锡矿
光电子学
分析化学(期刊)
化学
物理
天文
色谱法
作者
Suyu Ma,Hongkai Li,Jin Tae Hong,Han Wang,Xiaoshuang Lu,Yi Chen,Lin Sun,Fangyu Yue,Jens W. Tomm,Junhao Chu,Shiyou Chen
标识
DOI:10.1021/acs.jpclett.9b03227
摘要
By comparing optical spectral results of both Sn-rich and Sn-poor Cu2ZnSnS4 (CZTS) with the previously calculated defect levels, we confirm that the band-tail states in CZTS originate from the high concentration of 2CuZn + SnZn defect clusters, whereas the deep-donor states originate from the high concentration of SnZn. In Sn-rich CZTS, the absorption, reflectance, and photocurrent (PC) spectra show band-tail states that shrink the bandgap to only ∼1.34 eV, while photoluminescence (PL) and PC spectra consistently show that abundant CuZn + SnZn donor states produce a PL peak at ∼1.17 eV and abundant SnZn deep-donor states produce a PL peak near 0.85 eV. In contrast, Sn-poor CZTS shows neither bandgap shrinking nor any deep-donor-defect induced PL and PC signals. These results highlight that a Sn-poor composition is critical for the reduction of band-tailing effects and deep-donor defects and thus the overcoming of the severe open-circuit voltage (Voc) deficiency problem in CZTS solar cells.
科研通智能强力驱动
Strongly Powered by AbleSci AI