Te doping in the GaAs tunnel junction for GaInP/GaAs tandem solar cells

Heavily tellurium (Te)-doped GaAs layers with diethyltellurium (DETe) grown by metalorganic chemical vapor deposition (MOCVD) were investigated. The existence of Te-rich microprecipitates might degrade both the electrical and optical properties. Compared to Si doping, the tunnel junction diode doped with Te doping revealed lower tunneling resistance. A comparative study using both Si and Te doping in the GaAs tunnel junction of GaInP/GaAs tandem solar cells showed a higher efficiency for Te doping. Therefore, the GaAs tunnel junction with Te doping can be considered to improve the device performance of GaAs-based multi-junction solar cells.