Fabrication of n-ZnSe/p-Si/n-Si heterojunction phototransistor using IR furnace chemical vapour deposition and its optical properties analysis

An experimental study is presented involving the fabrication and analysis o f a relatively new structure n-ZnSe/p-Si/n-Si heterojunction phototransisto r having a high photo-current responsivity in the short-wavelength spectrum . Utilising photoluminescence :PL) spectroscopy and cyrosystems to investig ate the optical characteristics of the grown ZnSe epilayer, the dominant em ission peak was 444 nm (2.793 cV) with a FWHM of 28.3 mcV at 10 K due to ne ar-band-edge (NBE) excitation emission. Group III element indium was select ed as the n-type dopant for thermal diffusion on the ZnSe epilayer utilised to fabricate the studied device. The resulting photo-current responsivity was approximately 50 A/W at a bias voltage of V-CH = 15 V, with the highest photo-current responsivity occurring at a frequency of 470 nm. The study d emonstrates that n-ZnSc/p-Si/n-Si heterojunction phototransistors are capab le of functioning as short-wavelength photodetectors and have considerable potential in optoelectronic integrated circuit (OEIC) applications.