A Simple Chemical Route for the Synthesis of Low Cost UV‐sensor Using CdMgS Nanocrystalline Films

摘要

Nanocrystalline CdMgS films were deposited on glass substrate by chemical bath deposition (CBD) technique. A solution of cadmium nitrate, magnesium nitrate, trisodium citrate and thiourea were used to deposit nanocrystalline films. The preparative parameters like ion concentration, temperature, pH and stirring rate have been optimized for getting good quality thin films. The deposited nanocrystalline films are annealed in the air atmosphere for 1h at 600?°C. The prepared films were characterized by X‐ray diffraction (XRD) technique, scanning electron microscopy (SEM), UV‐Vis spectroscopy and Photoluminescence spectroscopy. X‐ray diffraction studies revealed the formation of face centered cubic structure. The crystalline size was determined using Scherrer formula which is found to be 26 nm and the dislocation density was evaluated using the high intense X‐ray diffraction peaks. The surface morphology studies showed that the film consists of nanocrystals. The films have high absorption in the UV‐A region (315-400 nm). A Photoluminescence spectrum shows an intense green emission at around 528 nm. The optical band gap of the film has been estimated to be 3.48 eV for the annealed films. The experimental results show that, CBD method allows the synthesis of nanocrystalline CdMgS films with high absorption of UV radiation in the UV‐A region.