Monocrystalline CdSexTe1-x/MgyCd1-yTe Double-Heterostructure Solar Cells Grown by Molecular Beam Epitaxy

Zheng Ju1, Xin Qi1, Xiaoyang Liu2, Tyler McCarthy1, Allison McMinn1, Razine Hossain1, Yong-Hang Zhang1 1School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ, United States /2Department of Physics, Arizona State University, Tempe, AZ, United States

Monocrystalline CdSexTe1-x/MgyCd1-yTe double-heterostructure (DH) solar cells with varying Se compositions in the absorber layers are grown on InSb substrates by using molecular beam epitaxy (MBE). The Se compositions are determined to be between 4%~11% through high-resolution X-ray diffraction (XRD) and photoluminescence (PL) measurements. Devices are fabricated by directly depositing an n-type indium tin oxide (ITO) on the CdSexTe1-x/MgyCd1-yTe DH before concluding with a silver metal contact. Among all the solar cells with CdSeTe absorbers, the devices with 4% Se incorporation in the absorber exhibit the best performance, achieving an average open-circuit voltage (VOC) of 0.92 V, short-circuit current density (JSC) of 25.8 mA/cm2, fill factor (FF) of 0.65 and efficiency of 15.5% without any anti-reflection coating (ARC).