Electrical Response of CdS Thin Film and CdS/Si Heterojunction to Gamma Radiation

Abstract

Gamma irradiation method has been used to change the electrical properties of CdS thin film. A specific dose ofγ-irradiation increases the activation energy of CdS thin film. In addition,γ-irradiation was used to change the sign of Hall coefficient,RH, of CdS thin film from negative to positive irrespective of temperature. The Hall mobility mechanism shows noticeable change afterγ-irradiation from decreasing to increasing with raising the temperature. In depth, analysis was done using capacitance-voltage measurement in order to realize the modification in the CdS/Si junction band gap afterγ-irradiation. Several parameters were also studied such as charge carrier concentration,ND, and flat band potential,Vfb. Theγ-irradiation was found to increase the concentration of the deep traps within the band gap of the CdS/Si heterojunction.

Gamma radiation effect on the structural and optical properties of CdS thin films prepared by spray pyrolysis technique

“…This is one of the major obstacles that reduces the current density of most solar cells and as a consequence hinders the performance of solar cells [6][7][8]. This problem could be solved via increasing the band gap of the window layer which could be accomplished by doping with other elements [8] or by irradiation which nowadays is considered one of the frequently used tools for modifying the optical and electrical properties of materials [9,10]. For applying CdS thin films in radiation dosimetry field, investigation of radiation impact on its physical properties is practically essential [11], and if the film properties change regularly with the radiation dose, then it can be applied as a dosimeter.…”

“…Many studies on the impact of radiation dose on the physical properties of CdS thin films have been reported. Balboul et al have prepared CdS thin films using electron beam evaporation method and subjected the films to 10 kGy up to 30 kGy of gamma dose and investigated the DC conductivity as well as the Hall mobility of the samples where the charge carriers type has turned from n-type to p-type at all doses and the DC conductivity has been decreased gradually with raising the gamma dose [10]. Abdel-Galil et al have also prepared CdS nanoparticles using the hydrothermal method and CdS/PVA nanocomposites have been synthesized via the solution casting method and an apparent decrease of CdS crystallite size upon exposure to gamma radiation has been observed starting at a dose of 10 kGy up to 30 kGy [12].…”