Thin film CdTe Photovoltaics (PV) is an important technology for the generation of utility scale solar electricity. With recent improvements, research scale small devices have recorded efficiency of 22.1% while modules with up to 18.64% efficiency have been produced. CdTe is a p-type absorber layer in such films. The band gap of CdTe is 1.45 eV which is near optimum for photovoltaic conversion. It also has a high coefficient of absorption which implies that a very thin film (~2 µm) is sufficient for complete absorption between 300 nm and 800 nm. In the field of research and development of low-cost solar energy converters, we proposed inorganic-organic solar cells in an all thin-film configuration deserve detailed investigation. For example, prospective materials for substitution of inorganic semiconductors in solar cells can be conductive polymers and photosensitive organic semiconductors. CdTe photovoltaics have been established as green, affordable, efficient and sustainable alternative to conventional energy sources. Incorporating organic materials into established photovoltaic technology such as CdTe would be of great interest as an approach to next generation photovoltaics. Moreover, the aim here was to combine the advantages of different material system to achieve higher efficiency as well as a low cost and more efficient manufacturability. In this tenure, a number of new devices were fabricated with CdTe photoabsorber layer and CdS window buffer layer with CdCl2 on Glass/TCO. Organic back contact layer of highly conductive polymers were deposited and investigated. The best obtained devise showed an open-circuit voltage of 795 mV, a short-circuit current of 22 mA/cm2 , Fill Factor of 72.5% and efficiency of 12.65 % under white light illumination with an intensity of 100mW/cm2 with reduced copper.
Note :- This Project was sanction and funded by the Department of Science and Technology, Govt. of India, and the Indo-U.S. Science and Technology Forum (IUSSTF) Dr. Milind Shrinivas got selected for the prestigious Bhaskara Advanced Solar Energy (BASE) Fellowship Program-2015 including other 9 scientists from all over India.