Small-polaron mediated recombination in titanium dioxide from first principles

• DOI: 10.1103/physrevresearch.5.023072
• Publication Date: 2023-05-01T14:16:50Z
• Authors: James A. Quirk; Keith P. McKenna
• Keywords: Titanium Dioxide

Nonradiative recombination leads to losses in efficiency optoelectronic devices such as photovoltaic cells and light-emitting diodes. Charges trapped at point defects or self-trapped a small polaron may act centers. Using various phases of titanium dioxide an example, we provide first-principles predictions that hole polarons the bulk crystal would exhibit significant rates with electrons conduction band. However, model grain boundary are predicted have much higher nonradiative rates, which can be attributed softer phonon modes vicinity well greater electron-phonon coupling. These findings ramifications materials other than dioxide, propose strategies reduce degree occur boundaries.