Abstract
In a period of only a few years, the power conversion efficiency of organic–inorganic perovskite solar cells has surpassed a value of 24.2%. However, a major drawback is the lack of long-term stability, which is partially related to the dissociation of organic cations under prolonged illumination. This degradation mechanism is not limited to ambient temperatures. At low temperatures (T = 5 K), illumination of methyl ammonium lead iodide (CH3NH3PbI3) thin films with a photon energy of Eph = 3.4 eV results in the formation of localized trap states located about 100 meV within the bandgap. These light-induced defects are metastable, and annealing at T ≥ 15 K removes the localized states. Defect creation is not limited to polycrystalline perovskites but is also observed in single-crystal CH3NH3PbI3. The experimental data are discussed in terms of a two-level model where the metastable state is separated from the annealed state by an energy barrier.
Original language | English |
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Article number | 1900216 |
Journal | Solar RRL |
Volume | 4 |
Issue number | 2 |
DOIs | |
Publication status | Published - Feb 1 2020 |
Externally published | Yes |
Keywords
- CHNHPbI
- light-induced defect generation
- low temperature
- perovskite
- single crystal
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Energy Engineering and Power Technology
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering