Past Research

Carrier Selective Crystalline Solar Cells

The need for clean and renewable energy resources has provided a boost to research in the field of photovoltaics. Silicon solar cells dominate the market due to their robustness and ease of availability among other favourable material properties. But conventional p-n junction solar cells require high thermal budget and suffer from high junction recombination. These disadvantages can be overcome in junction-less solar cells.

Our group focusses on the development and analysis of carrier selective contact (CSC) based junction-less Si solar cells that utilize transition metal oxides as the charge selective layers. This work is in  collaboration with IIT Mandi (Prof. Kunal Ghosh). CSC solar cells show potential to achieve the thermodynamic efficiency limit of silicon solar cells with a low thermal budget. We have studied the design and development of CSC solar cells using numerical simulations [1] and analytical models in addition to their experimental fabrication. Numerical simulations indicate that passivated CSC cells can achieve an efficiency greater than 25% for realistic surface recombination values of up to 100 cm/s. Our current focus is on the fabrication of passivated CSC cells using various transition metal oxide charge selection layers.

In order to evade parasitic absorption losses in CSC solar cells and avoid front metal shading loss, we have proposed an improved architecture with carrier selective layers at the rear end of the solar cell. We call this device structure as a carrier selective back contact (CSBC) solar cell. We have developed numerical simulation models for the CSBC solar cell [2] and are presently working towards developing its analytical model.

 Publications and Patent

  1. Astha Tyagi, Kunal Ghosh, Anil Kottantharayil, Saurabh Lodha, “Performance Evaluation of Passivated Silicon Carrier Selective Contact Solar Cell”, IEEE Transactions on Electron Devices, Vol. 65, 1 (2018). Link
  2. Astha Tyagi, Kunal Ghosh, Anil Kottantharayil, and Saurabh Lodha, “Carrier Selective Back Contact (CSBC) Solar Cell using Transition Metal Oxides”, IEEE-PVSC, June 25-30, Washington DC, USA, 2017.

  3. Astha Tyagi, Kunal Ghosh, Anil Kottantharayil, Saurabh Lodha, “Solar cell and structure thereof”, Indian patent filed (Application No. 201721004570), Feb 2018.