The electronic structure of metal oxide/organo metal halide perovskite junctions in perovskite based solar cells

Abstract

Cross-sections of a hole-conductor-free CH3NH3PbI3 perovskite solar cell were characterized with Kelvin probe force microscopy. A depletion region width of about 45 nm was determined from the measured potential profiles at the interface between CH3NH3PbI3 and nanocrystalline TiO2, whereas a negligible depletion was measured at the CH3NH3PbI3/Al2O3 interface. A complete solar cell can be realized with the CH3NH3PbI3 that functions both as light harvester and hole conductor in combination with a metal oxide. The band diagrams were estimated from the measured potential profile at the interfaces, and are critical findings for a better understanding and further improvement of perovskite based solar cells.

Establishing the limits of efficiency of perovskite solar cells from first principles modeling

“…Interface and surface dipoles, defects and sample inhomogeneities result in substantial differences in available experimental data. For example, the depletion layer is reported to be somewhere between 45 to 300 nm2223, indicating that level alignments play a crucial role for the carrier concentrations and for the potential gradient in the perovskite. The calculation of the natural band alignment from first principles using core levels or by inspecting how the average electrostatic potential changes on a site in different environments has been treated extensively in the literature2425.…”

Efficient Carrier Separation and Intriguing Switching of Bound Charges in Inorganic–Organic Lead Halide Solar Cells

“…The potential value of perovskite has a similar potential barrier value as the CIGS or CZTSe thin-films. Moreover, we analyzed the potential 22 The potential barrier in the perovskite GBs discloses the hole accumulation and could play a minor effect in the performance of the solar cells. 22 The potential value at the GBs of this group is very different ours due to the difference in the n-type layer.…”

Large-Size CH3NH3PbBr3 Single Crystal: Growth and In Situ Characterization of the Photophysics Properties

“…The current mapping was presented in Figure 5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 the interface of grain boundaries, due to grain potential barrier effect, making the real current density of the solar cells device much smaller than theoretical value 47,48 .…”