Dear all:
I would like to invite you for my preliminary examination (or free coffee and snacks).

Date: November 20th, 2014
Time: 3:30 PM
Venue: Wang 1004

Title: Fundamental and Practical Limits of Heterojunction Solar Cells

Abstract:
The large-scale deployment of PV technology is very sensitive to the material and process costs. There are several potential candidates of p-n heterojunction (HJ) solar cells competing for higher efficiencies with lower material and process costs. However, these systems are generally more complex, involve diverse material systems and are not as well understood. Often, the direct translation of classical p-n homojunction theory to understand a p-n HJ system, causes misinterpretation, suffers from lack of self-consistency and ultimately renders it useless for modeling and characterization of these solar cells. Hence, there is a strong need to redefine/reinterpret the modeling and characterization of HJ solar cells, which would lead to a material system independent and self-consistent framework.

Towards this goal, we explore the physics, interpret characterization experiments of p-n HJs, using Silicon HJ (HIT) solar cell. In this work, we will (1) identify the technology bottlenecks, (2) provide a self-consistent multi-probe approach to extract the HJ parameters which influence the bottlenecks, and (3) propose guidelines to reach practical device efficiency limits.  Finally, we propose to investigate (1) the fundamental limits of HJ solar cells and (2) provide guidelines for further improvement of module level efficiencies.

Thank you,
Raghu Vamsi K. Chavali
PhD Student
ECE, Purdue University