Dominating loss mechanisms were identified at hole-selective buried interfaces engineered with carbazole-based self-assembled monolayers between a metal halide perovskite absorber and a conductive metal oxide. The analysis of surface photovoltage transients with a minimalistic kinetic model allowed for the extraction of interfacial electron trap densities and hole transfer rates and their correlation with open-circuit voltages and fill factors of the corresponding highefficiency solar cells is demonstrated.

Understanding the type, formation energy and capture cross section of defects is one of the challenges in the field of organometallic halide perovskite (OMHP) devices. Currently, such understanding is limited, restricting the power conversion efficiencies of OMHPs solar cells from reaching their Shockley-Queisser limit. In more matured semiconductors like Si, the knowledge of defects was one of the major factor in successful technological implementation. This knowledge and its control can make a paradigm in development of OMHP devices. Here, we report on deep level (DL) defects and their effect on free charge transport properties of single crystalline methylammonium lead bromide perovskite (MAPbBr3). In order to determine DL activation energy and capture cross section we used photo-Hall effect spectroscopy (PHES) with enhanced illumination in both steady-state and dynamic regimes. This method has shown to be convenient due to the direct DL visualization by sub-bandgap photo-excitation of trapped carriers. DLs with activation energies of EV + 1.05 eV, EV + 1.5 eV, and EV + 1.9 eV (or EC -1.9 eV) were detected. The hole capture cross section of h = 4 × 10 -17 cm 2 is found using photoconductivity relaxation after sub-bandgap photo-excitation. Here, we found the DL defects responsible for non-radiative recombination and its impact on band alignment for the first time. Additionally, the transport properties of single crystal MAPbBr3 is measured by Time of Flight

Halide perovskites have undergone remarkable developments as highly efficient optoelectronic materials for a variety of applications. Several studies indicated the critical role of defects on the performance of perovskite devices. However, the parameters of defects and their interplay with free charge carriers remain unclear. In this study, we explored the dynamics of free holes in methylammonium lead tribromide (MAPbBr3) single crystals using the time-of-flight (ToF) current spectroscopy. By combining ToF spectroscopy and Monte Carlo simulation, three energy states were detected in the bandgap of MAPbBr3. In addition, we found the trapping and detrapping rates of free holes ranging from a few microseconds to hundreds of microseconds. Contrary to previous studies, we revealed a strong detrapping activity of traps. We showed that these traps substantially affect the transport properties of MAPbBr3, including mobility and mobility-lifetime product. Our results provide an insight on charge transport properties of perovskite semiconductors.