PROJECT PROFILE: Colorado School of Mines 2 (PVRD2)

Project Name: Revealing the Mechanism of Light Induced Degradation and Regeneration of P-type Czochralski Monocrystalline Silicon
Funding Opportunity: PVRD2
SETO Subprogram: Photovoltaics
Location: Golden, CO
SETO Award Amount: $225,000
Awardee Cost Share: $25,000
Principal Investigator: Sumit Agarwal

This project employs advanced spectroscopic tools to explore boron-oxygen (B-O) related defects in p-type Czochralski monocrystalline silicon (Cz c-Si) and inform processing strategies to permanently suppress these defects and improve cell energy output. Early-stage materials research is improving understanding of the hydrogenation and dehydrogenation of B-O complexes, as well as clarifying their bonding configurations and evolution during intense illumination.

Approach

The research team is tracking the hydrogenation and dehydrogenation of B-O complexes in boron-doped Cz c-Si, and relating these measurements to light-stimulated electron spin resonance methods to explain boron-related paramagnetic complexes and their evolution. Combined with other techniques such as Sinton lifetime measurements and areal photoluminescence mapping, the team will establish the role of atomic hydrogen in defect suppression in boron-doped Cz c-Si. 

Innovation

This project will help to develop a better understanding of the light-induced degradation that occurs in passivated emitter rear contact cells. As these cells continue to replace aluminum back surface field cells, this research will establish two spectroscopic techniques to understand the regeneration of boron-doped p-type Cz c-Si. This will help assess the long-term stability of the cell and lead to better processing strategies to permanently suppress the defects for the field lifetime of the cell.