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 of a relatively new structure n-ZnSe/p-Si/n-Si heterojunction phototransistor having a high photo-current responsivity in the short-wavelength spectrum. Utilising photoluminescence (PL) spectroscopy and cryosystems to investigate the optical characteristics of the grown ZnSe epilayer, the dominant emission peak was 444 nm (2.793 eV) with a FWHM of 28.3 meV at 10 K due to near-band-edge (NBE) excitation emission. Group III element indium was selected 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 demonstrates that n-ZnSc/p-Si/n-Si heterojunction phototransistors are capable of functioning as short-wavelength photodetectors and have considerable potential in optoelectronic integrated circuit (OEIC) applications