Abstract: Aluminum doped Zinc Selenide ZnSe/n-Si thin films of (250±20 nm) thickness with (0.01, 0.02 and 0.03) are depositingon the two type of substrate (glass and n-Si) to manufacture (ZnSe/n-Si) solar cell through using thermal vacuum evaporation procedure. Physical and optoelectronic properties were examined for the samples. X-ray and AFM techniques are using to study the structure properties. The energy band gap of as-deposited ZnSe thin films for changed dopant ratio were ranging from (2.6-2.68 eV). The results of Hall effect show that pure and doping films were (p-type) and the concentration of the charge carriers and the carriers mobility increases with increase Al-dopant ratio. The (C-V) measurement have shown that the heterojunction were of abrupt type. In addition, the I-V characteristics of ZnSe/Si heterojunctions show the forward dark current varies with applied voltage, besides the saturation current and the ideality factor are determined under different doping percentage. Also, the (I-V) characteristic for ZnSe/Si heterojunction show that the forward current at dark varies with applied voltage and the Isc and Voc have been studied. The photoelectric properties designated an increase light current of heterojunctions with cumulativeAl-dopant and I-V characteristics under illumination showed that the heterojunction (ZnSe: Al (0. 3%)/Si) have ahigh efficiency.