Atsugi Research Center , Solar Frontier K. K. , Atsugi , Kanagawa 243-0206 , Japan.
ACS Appl Mater Interfaces. 2019 Feb 20;11(7):7539-7545. doi: 10.1021/acsami.8b19344. Epub 2019 Feb 11.
Cd-free Cu(In,Ga)(S,Se) (CIGSSe) solar cells with a structure of glass/Mo/CIGSSe/ZnMg O (buffer)/ZnMg O:Al (TCO), fabricated by an all dry process, are characterized using ultraviolet light excited time-resolved photoluminescence (UV-TRPL). The impact of bandgap energy ( E) values of buffer and transparent conductive oxide (TCO) layers, denoted by E of buffer and TCO, is examined. The E values of buffer and TCO layers are kept almost similar and varied from 3.30 to 3.94 eV. In this work, UV-TRPL measurement is performed to examine the UV-TRPL carrier lifetimes near the ZnMg O buffer/CIGSSe interface in the solar cell structure. It is revealed that the UV-TRPL carrier lifetimes near the ZnMg O buffer/CIGSSe interface in Cd-free solar cells are increased upon enhancing the E of buffer and TCO from 3.30 to 3.94 eV, thus increasing the open-circuit voltage and fill factor. Additionally, short-circuit current density is enhanced up to about 38 mA/cm owing to the highly transparent ZnMg O/ZnMg O:Al layers. Ultimately, an 18.5%-efficient Cd-free solar cell with the E of buffer and TCO of 3.94 eV, prepared by an all dry process, is fabricated, which has the same level of 18.3% for the reference solar cell (glass/Mo/CIGSSe/CdS/ZnO/ZnO:Al).
无镉铜铟镓硒（CIGSSe）太阳能电池采用全干法工艺制备，结构为玻璃/Mo/CIGSSe/ZnMgO（缓冲层）/ZnMgO:Al（TCO），采用紫外光激发时间分辨光致荧光（UV-TRPL）进行了表征。考察了缓冲层和透明导电氧化物（TCO）层的能带隙能量（E）值，分别表示为缓冲层 E 和 TCO E 的影响。缓冲层和 TCO 层的 E 值保持几乎相同，从 3.30 到 3.94 eV 变化。在这项工作中，进行了 UV-TRPL 测量，以检查太阳能电池结构中 ZnMgO 缓冲层/CIGSSe 界面附近的 UV-TRPL 载流子寿命。结果表明，在无镉太阳能电池中，当缓冲层和 TCO 的 E 从 3.30 增加到 3.94 eV 时，ZnMgO 缓冲层/CIGSSe 界面附近的 UV-TRPL 载流子寿命增加，从而提高开路电压和填充因子。此外，由于高度透明的 ZnMgO/ZnMgO:Al 层，短路电流密度增加到约 38 mA/cm。最终，通过全干法制备了 E 值为 3.94 eV 的无镉 18.5%高效太阳能电池，与参考太阳能电池（玻璃/Mo/CIGSSe/CdS/ZnO/ZnO:Al）的 18.3%水平相当。
