CW and pulsed electrically detected magnetic resonance spectroscopy at 263 GHz/12 T on operating amorphous silicon solar cells

TL;DR

This paper introduces a high-frequency, high-field EDMR spectroscopy setup at 263 GHz/12 T, enabling detailed study of spin-dependent transport in amorphous silicon solar cells at cryogenic temperatures.

Contribution

The development of a novel 263 GHz/12 T EDMR setup allows improved resolution and insight into spin-dependent processes in amorphous silicon solar cells compared to previous methods.

Findings

Enhanced resolution of spin-dependent signals at 263 GHz

Identification of hopping and recombination processes at different temperatures

Detailed characterization of spin states involved in transport

Abstract

Here we describe a new high frequency/high field continuous wave and pulsed electrically detected magnetic resonance (CW EDMR and pEDMR) setup, operating at 263 GHz and resonance fields between 0 and 12 T. Spin dependent transport in illuminated hydrogenated amorphous silicon p-i-n solar cells at 5 K and 90 K was studied by in operando 263 GHz CW and pEDMR alongside with complementary X-band CW EDMR. Benefiting from the superior resolution at 263 GHz, we were able to better resolve EDMR signals originating from spin dependent hopping and recombination processes. 5 K EDMR spectra were found to be dominated by conduction and valence band tale states involved in spin dependent hopping, with additional contributions from triplet exciton states. 90 K EDMR spectra could be assigned to spin pair recombination involving conduction band tail states and dangling bonds as dominating spin dependent transport process, with additional contributions from valence band tail and triplet exciton states.