Improving CdTe-Based Thin-Film Solar Cell Efficiency with the Oxygenated CdSe Layer Prepared by Sputtering Process

Sputtered CdSe window layer can improve the short-circuit current density (J(sc)) of CdTe-based thin-film solar cell, however, meanwhile degrade the open-circuit voltage (V-oc) and fill factor (FF). Herein, an oxygenation process is introduced during CdSe sputtering to improve this window layer's property for better device performance. The influence of oxygen on the CdSe is similar as the effect of oxygen on CdS. Incorporation of oxygen into the CdSe film promotes the formation of CdSeO3 phase. Both V-oc and FF of the CdTe solar cells are improved due to the formation of CdSeO3, and high efficiency (Eff.) of 18.6% is achieved. Efficiency improvement at module level is also demonstrated after applying the CdSe:O process in production line. This progress contributes to the CdTe-based thin-film module production for further efficiency improvement and cost reduction.