Enhancement Open Circuit Voltage of Calcium Titanate AR Coated Magnesium Solar Cell

Abstract

The present research aims to enhance the open circuit voltage of fabricated solar cell through Anti–Reflection (AR) coating on the cell substrate. Solar cell is fabricate using ITO Glass, titanium dioxide, magnesium and redox. Calcium Titanium Oxide (CaTiO3) is chosen as the AR coating material for constructing thin film layer on fabricated solar cell. Selected AR coating material have unique features such as orthorhombic, biaxial, non-radioactive and non-magnetic with electron bulk density of 3.91 g/cm3 respectively. Commonly, voltage generation of the multi crystalline solar cell is low (12% to 14%) due to much reflection of inward sun radiation. Deposition of AR coating on the substrate (fabricated solar cell) can minimize the reflection loss of sun radiation. The maximum improvement in solar cell efficiency after AR coating has been reported as 19.3%. Sputter coating technique is more favorable for thin film coating due to its salient features like uniform coating thickness controlled by time. This uniform coating thickness absorbs more sun radiation. Radio Frequency (RF) magnetron sputter coating technique is utilized in the current research to deposit CaTiO3 on solar cells. Prior to coating, the AR material is pelletized using Universal Testing Machine (UTM). The substrate are coated under varying time duration of 15-minutes, 30-minutes and 45-minutes in order to analyze the variation in open circuit voltage. The deposition of coating on the substrate are confirmed using SEM and FESEM. Open circuit voltage of controlled atmosphere studies for pure and AR coated solar cells (fabricated) are examined. Controlled atmosphere tests of AR coated thin films are conducted by placing the substrate inside a solar simulator and the solar simulator consist of IR thermometer (To measure Temperature), solar power meter (To measure Radiation) and multimeter (To measure Open circuit voltage). Neodym daylight lamp is used to control the radiation in solar simulator. The improvement in cell voltage proves that thin film AR coating considerably minimizes the reflective loss.