Research: Flexible Photovoltaics and Light-trapping in Photonic Crystals

My present research focuses on photonic crystal (semiconductor of light) mediated strong light-matter interaction. Photonic crystals are periodic structures, capable of controlling the flow of light in unprecedented ways. While most of the applications of photonic crystal rely on the suppression of Electromagnetic density of states (in other words, existence of photonic band-gap), a suitably designed photonic crystal can greatly increase Electromagnetic density of states over a specified spectral range and thus, acts as a very efficient light-trap enabling a number of applications.

In a recent research based on this principle, I, along with Prof. Sajeev John, have proposed a new paradigm of high-efficiency silicon solar cell design that exploits the wave nature of sunlight. This design enables power conversion efficiency beyond 30%, using a 15 micron-thick, flexible, photonic crystal silicon sheet. Wave-interference in photonic crystals provides a new mechanism for solar energy capture, outside the framework of conventional ray-optics-based light trapping. Photonic crystal cell, 10-15 times thinner than the world-record-setting solar cells, enables thin-film silicon to leapfrog ahead of competing technologies and well beyond the efficiency of any single material cell of any thickness. Already, a number of industries have taken interest in this research and we are looking at an exciting time ahead!

Publications

Announcement: I am starting a new research group, PQUAD (Photonics and QUAntum Devices), @IIITD. If you are interested in a PhD position (research area 1: All-optical circuit design, research area 2: High-efficiency, flexible photovoltaics), email me your CV.
PG and UG students of IIIT-D: send an email/ drop by my office in case you are interested in working with me (topic 1: All-optical circuit design, topic 2: High-efficiency, flexible photovoltaic technologies, topic 3: Development of CAD tools for simulation and design of heterojunction solar cells)