CHEMICAL SYNTHESIS OF WIDE BAND GAP N-TIO2 AND P-CUSCN AS A HETEROJUNCTION PARTNERS FOR DETECATION OF LIQUEFIED PETROLEUM GAS (LPG) AT ROOM TEMPERATURE

摘要

First time attempt is made to form bi-layer structure device consisting of first Ti02 layer by doctor blade technique with step annealing at 400-500 °C followed by CuSCN layer by SILAR method to form the heterojunction as well as to use this heterojunction to sense the liquefied petroleum gas (LPG) at room temperature. The reports are available for the synthesis of individual Ti02 layer by doctor blade technique where as CuSCN layer by SILAR method. No report is available to form this type of bi-layer structure device as well as for LPG sensor. The formed bi-layer structure was characterized by using structural, surface morphological, compositional studies and optimized to form the better heterojunction device. For the fabrication of heterojunction, thickness of each material is to be optimized in order to get high quality heterojunction. After the fabrication of heterojunctions, current-voltage (I-V) characteristics were studied in order to evaluate various electrical parameters to test the diode quality. The gas sensing performance at different concentrations of LPG is carried out at room temperature by current-voltage (I-V) characteristics under the forward bias condition. Lastly, the performance of LPG sensors is evaluated in terms of their sensitivity. The sensitivity about 67 % was achieved at 1000 ppm of LPG concentration at room temperature along with stability test for almost 12 days. Also the response time and recovery time were observed with remarkable achievements.