<abstract xmlns="http://www.w3.org/1999/xhtml">The main drawback of the methylammonium lead halide perovskite solar cells is their degradation in ambient atmosphere. To investigate ambient-air-induced cell degradation, spectral dependencies of open-circuit voltage (<italic>V</italic><italic>OC</italic>), fill factor (FF) and the power conversion efficiency (PCE) have been acquired (for the first time reported in literature).Our custom-made measurement system allowed us to perform measurements of the abovementioned entities <italic>in situ</italic> directly in vacuum during and after thermal deposition of the electrode. We also studied how these parameters in vacuum changed after cell exposure to ambient air for 85 min (50 nm top electrode) and for 180 min (100 nm top Ag electrode). For fresh CH3NH3PbI3–xClx cell (never been in open air) with very high shunt resistance of 3·107 Ω·cm2 (with practically no shorts and therefore FF could be determined mainly by charge carrier recombination processes) we found that FF in vacuum increased along with an increase of the incident photon energy from 0.55 at 760 nm up to 0.82 at 400 nm. Hypothesis considering hot polaron participation in charge carrier photogeneration and recombination processes as well as another competing hypothesis were offered as possible explanations for the observed FF increase.The kinetics of short-circuit photocurrent EQE with a change in pressure was also investigated. It was also shown that perovskite solar cell degradation could be noticeably reduced by increasing the top Ag electrode thickness to at least 100 nm, which could possibly facilitate the usual encapsulation process.</abstract>

The main drawback of the methylammonium lead halide perovskite solar cells is their degradation in ambient atmosphere. To investigate ambient-air-induced cell degradation, spectral dependencies of open-circuit voltage (VOC), fill factor (FF) and the power conversion efficiency (PCE) have been acquired (for the first time reported in literature).Our custom-made measurement system allowed us to perform measurements of the abovementioned entities in situ directly in vacuum during and after thermal deposition of the electrode. We also studied how these parameters in vacuum changed after cell exposure to ambient air for 85 min (50 nm top electrode) and for 180 min (100 nm top Ag electrode). For fresh CH3NH3PbI3–xClx cell (never been in open air) with very high shunt resistance of 3·107 Ω·cm2 (with practically no shorts and therefore FF could be determined mainly by charge carrier recombination processes) we found that FF in vacuum increased along with an increase of the incident photon energy from 0.55 at 760 nm up to 0.82 at 400 nm. Hypothesis considering hot polaron participation in charge carrier photogeneration and recombination processes as well as another competing hypothesis were offered as possible explanations for the observed FF increase.The kinetics of short-circuit photocurrent EQE with a change in pressure was also investigated. It was also shown that perovskite solar cell degradation could be noticeably reduced by increasing the top Ag electrode thickness to at least 100 nm, which could possibly facilitate the usual encapsulation process.

Perovskite CH3NH3PbI3–XClx Solar Cells. Experimental Study of Initial Degradation Kinetics and Fill Factor Spectral Dependence

Latvian Journal of Physics and Technical Sciences

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Perovskite CHNHPbICl Solar Cells. Experimental Study of Initial Degradation Kinetics and Fill Factor Spectral Dependence

The main drawback of the methylammonium lead halide perovskite solar cells is their degradation in ambient atmosphere. To investigate ambient-air-induced cell...

Perovskite CH₃NH₃PbI_3–XCl_x Solar Cells. Experimental Study of Initial Degradation Kinetics and Fill Factor Spectral Dependence

Published Online: Jan 29, 2021

Page range: 53 - 69

DOI: https://doi.org/10.2478/lpts-2021-0006

Keywords
Degradation kinetics, fill factor spectral dependence, lead halide perovskite, power conversion efficiency, solar cells

© 2021 I. Kaulachs et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Perovskite CH3NH3PbI3–XClx Solar Cells. Experimental Study of Initial Degradation Kinetics and Fill Factor Spectral Dependence

Published Online: Jan 29, 2021

Page range: 53 - 69

DOI: https://doi.org/10.2478/lpts-2021-0006

KeywordsDegradation kinetics, fill factor spectral dependence, lead halide perovskite, power conversion efficiency, solar cells

© 2021 I. Kaulachs et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Perovskite CH₃NH₃PbI_3–XCl_x Solar Cells. Experimental Study of Initial Degradation Kinetics and Fill Factor Spectral Dependence

Keywords
Degradation kinetics, fill factor spectral dependence, lead halide perovskite, power conversion efficiency, solar cells