Utilization of Temperature-Sweeping Capacitive Techniques to Evaluate Band Gap Defect Densities in Photovoltaic Perovskites

Almora Rodriguez O, García-Batlle M, Garcia-Belmonte G (2019)


Publication Type: Journal article, Letter

Publication year: 2019

Journal

Book Volume: 10

Pages Range: 3661-3669

URI: https://pubs.acs.org/doi/10.1021/acs.jpclett.9b00601

DOI: 10.1021/acs.jpclett.9b00601

Abstract

Capacitive techniques, routinely used for solar cell parameter extraction, probe the voltage-modulation of the depletion layer capacitance isothermally as well as under varying temperature. Also defect states within the semiconductor band-gap respond to such stimuli. Although extensively used, capacitive methods have found difficulties when applied to elucidate bulk defect bands in photovoltaic perovskites. This is so because perovskite solar cells (PSCs) actually exhibit some intriguing capacitive features hardly connected to electronic defect dynamics. The commonly reported excess capacitance observed at low frequencies is originated by outer interface mechanisms and has a direct repercussion on the evaluation of band-gap defect levels. Starting by updating previous observations on Mott-Schottky (MS) analysis in PSCs, it is discussed how the thermal admittance spectroscopy (TAS) and the deep level transient spectroscopy (DLTS) characterization techniques present spectra with overlapping or even “fake” peaks caused by the mobile ion-related, interfacial excess capacitance. These capacitive techniques, when used uncritically, may be misleading and produce wrong outcomes.

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APA:

Almora Rodriguez, O., García-Batlle, M., & Garcia-Belmonte, G. (2019). Utilization of Temperature-Sweeping Capacitive Techniques to Evaluate Band Gap Defect Densities in Photovoltaic Perovskites. Journal of Physical Chemistry Letters, 10, 3661-3669. https://doi.org/10.1021/acs.jpclett.9b00601

MLA:

Almora Rodriguez, Osbel, Marisé García-Batlle, and Germà Garcia-Belmonte. "Utilization of Temperature-Sweeping Capacitive Techniques to Evaluate Band Gap Defect Densities in Photovoltaic Perovskites." Journal of Physical Chemistry Letters 10 (2019): 3661-3669.

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