Photostability and photodegradation process in colloidal CsPbI3 quantum dots

All-inorganic CsPbI3 perovskite quantum dots (QDs) have attracted intense attention for the application in photovoltaics and optoelectronic applications due to their phase stability and great photoluminescence (PL) properties. However, the their photostability is still to be investigated in detail. In this thesis work, we studied the photostability of the CsPbI3 QDs suspended in hexane and found light illumination would induce photodegradation of CsPbI3 QDs. The steady-state spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and transient-absorption spectroscopy (TA) verified that light illumination would lead to the collapse of the CsPbI3 QDs’surface and the emergence of Pb0, which is a trapped state leading to the quench of PL and dramatic decrease of quantum yield. Our work provides some insight of the photodegradation process in CsPbI3 QDs and could lead to the optimization of such QDs towards device applications.