CdS/CdTe薄膜太阳电池的深能级瞬态谱和光致发光研究

Deep level transient spectroscopy and photoluminescence studies of CdS/CdTe thin film solar cells

用深能级瞬态谱和光致发光研究了无背接触层的CdS/CdTe薄膜太阳电池的杂质分布和深能级中心.得到了净掺杂浓度在器件中的分布.确定了两个能级位置分别在EV+0.365eV和EV+0.282eV的深中心,它们的浓度分别为1.67×1012cm-3和3.86×1011cm-2,俘获截面分别为1.43×10-14cm2和1.53×10-16cm2.它们来源于以化学杂质形式存在的Au和(或)TeCd-复合体,或与氩氧气氛下沉积CdTe时的氧原子相关.

Impurities and deep levels in CdS/CdTe thin film solar cells with no back-contact layer were studied by deep level transient spectroscopy and photoluminescence. They could lower the device performance notably. Distribution of net carrier concentration was obtained. Two deep levels at EV＋0.365 eV and EV＋0.282 eV were determined with concentration of 1.67×10 12 cm-3 and 3.86×10 11 cm-3 ,respectively,and with capture cross section of 1.43×10-14 cm2 and 1.53×10-16 cm2,respectively. They are attributed to chemical impurities like Au and/or a singly charged tellurium vacancy complex,or related to O atoms introduced by the deposition of CdTe in O2 and Ar ambient.