Metal-halide perovskites are known to degrade under UV illumination at wavelengths seen in solar radiation.
At far higher energy irradiation as that used in Ultraviolet photoemission spectroscopy measurement (photon energy at 21.22 eV(He I) and 40.81 eV (He II)), will perovskites undergo some type of degradation/decomposition? Does the degradation happen immediately at illumination or occur over a long term?
How robust/stable is metal-halide perovskite under high energy photon bombardment?
Hello,
From my experience, I successfully performed UPS measurements and determined valence band position of a 2D perovskite thin film. It was consistent with a literature data.
However, there is a couple of tricks. As you know, He radiation penetration is about 2-3nm. So any little contamination of a surface will cause inaccurate measurements. Normally, etching ion gun is used to clean a specimen surface before measurements. Though the perovskite surface wont withstand that. Therefore your samples must be super fresh.
Also, your samples must me deposited on a conductive surface such as ITO/FTO.
My samples were disposed after measurements, so I didn't check its condition, but I wouldn't say that degradation happens immediately.
Hope it helps you
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