Magnesium zinc oxide (MZO, Mg_xZn_1-xO) is a leading emitter for CdTe-based solar cells due to its transparency and the ability to tune its conduction band offset with the absorber. Devices employing alloyed cadmium selenide telluride (CST, CdSe_yTe_1-y) absorbers achieved high efficiency (>19%) using MZO deposited by reactive sputtering over a broad composition range (3.68–3.92 eV, x: 0.20–0.35). Minimal differences in implied and measured open circuit voltage indicate that the contacts are well passivated and highly selective across the spectrum of MZO employed. Device performance insensitivity to MZO composition, which is not observed in CdTe devices, is attributed to the formation of an oxygenated interface layer. Se volatility creates a group VI deficiency at the interface that drives O migration from the MZO into the absorber. This introduces conductivity in the emitter not present in its as-deposited state, contributing to the exceptional performance observed. It is shown that the quality of device passivation depends on the oxidation state of the as-deposited MZO such that intelligent control and management of the reactive sputtering process is required.

氧化镁锌 (MZO, Mg _x Zn _1-x O) 是 CdTe 太阳能电池的主要发射体，因为它具有透明性，并且能够通过吸收体调整其导带偏移。采用合金化硒化碲化镉 (CST, CdSe _y Te _1-y) 吸收器使用通过反应溅射沉积的 MZO 在广泛的组成范围 (3.68–3.92 eV, x: 0.20–0.35) 上实现了高效率 (>19%)。隐含的和测量的开路电压的最小差异表明触点在所采用的 MZO 范围内被很好地钝化和高度选择性。器件性能对 MZO 成分不敏感，这在 CdTe 器件中未观察到，归因于氧化界面层的形成。Se 挥发性在界面处产生 VI 族缺陷，从而推动 O 从 MZO 迁移到吸收器中。这会在不存在于其沉积状态的发射体中引入导电性，从而有助于观察到卓越的性能。