Tuning the Amount of Oxygen Vacancies in Sputter‐Deposited SnO x films for Enhancing the Performance of Perovskite Solar Cells

Autor: Hongxia Wang, Tuquabo Tesfamichael, Nima Khoshsirat, Ken Ostrikov, Ngoc Duy Pham, Fawad Ali, H. Jonathan Bradford, John Bell
Rok vydání: 2018
Předmět:
Zdroj: ChemSusChem. 11:3096-3103
ISSN: 1864-564X
1864-5631
DOI: 10.1002/cssc.201801541
Popis: This work demonstrates the effect of oxygen vacancies in SnOx thin films on the performance of perovskite solar cells. Various SnOx films with different amounts of oxygen vacancies were deposited by sputtering at different substrate temperatures (25–300 °C). The transmittance of the films decreased from 82 to 66 % with increasing deposition temperature from 25 to 300 °C. Both X-ray photoelectron spectroscopy and electron-spin resonance spectroscopy confirmed that a higher density of oxygen vacancies was created within the SnOx film at a high substrate temperature, which caused narrowing of the SnOx bandgap from 4.1 (25 °C) to 3.74 eV (250 °C). Combined ultraviolet photoelectron spectroscopy and UV/Vis spectroscopy showed an excellent conduction band position alignment between the methylammonium lead iodide perovskite layer (3.90 eV) and the SnOx electron transport layer deposited at 250 °C (3.92 eV). As a result, a significant enhancement of the open-circuit voltage from 0.82 to 1.0 V was achieved, resulting in an increase of the power conversion efficiency of the perovskite solar cells from 11 to 14 %. This research demonstrated a facile approach for controlling the amount of oxygen vacancies in SnOx thin films to achieve a desirable energy alignment with the perovskite absorber layer for enhanced device performance.
Databáze: OpenAIRE
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