Studies on Electron Beam Evaporated Undoped In and Zn doped CdSe thin films for Photo Electro Chemical Solar cell device

Abstract

The present investigation deals with the characterization of undoped and doped CdSe films for photoelectrochemical (PEC) solar cell device. CdSe films were deposited by electron beam evaporation (EBE) unit on glass substrates at RT and then annealed at 100, 200 and 300 °C. These films were characterized for their structural, surface morphological, electrical and optical properties. The XRD microstructural results reveal the device quality nature of these nano grained films. SEM/AFM morphology results show the device quality nature of CdSe films annealed at 200oC. The formation of high quality CdSe films with nano grain size distribution was revealed by the PL emission studies, Raman spectral results and FT-IR vibrational assignments. Annealed films showed considerable influence in their optical and structural properties, which provided improvement in efficiency. newlineAs the CdSe film preparation has been optimized as 200°C for all the depositions. In this work, we mainly discuss experimental data for n-doped CdSe thin films with optimized substrate temperature 200 oC. The electrical and optical properties of semiconductors are strongly influenced by the doping process. Here Zn and In doped CdSe films were deposited and the crystallite variation was studied for doping effect. Optical band gap values are found to be modified by doping. Indium and zinc doping concentration was taken as 10%, 20% and 30% introduced into the CdSe matrix. It leads to nanoparticles with different band gaps and thus different electronic properties from the undoped nanoparticles. newlinePhoto electrochemical (PEC) solar cells were fabricated using the annealed CdSe, CdSe:In and CdSe:Zn electrodes and the spectral response and current-voltage output results are studied. The current - voltage (I-V) plot is drawn and Isc and Voc values were obtained from the plot, the fill factor and efficiency were calculated from the plot. From the results, observed that CdSe:Zn and Cdse:In films with 10%, concentrations are good for the fabrication of PEC solar cell