Suppressed decomposition of organometal halide perovskites by impermeable electron-extraction layers in inverted solar cells

Abstract

The area of thin-film photovoltaics has been overwhelmed by organometal halide perovskites. Unfortunately, serious stability concerns arise with perovskite solar cells. For example, methyl-ammonium lead iodide is known to decompose in the presence of water and, more severely, even under inert conditions at elevated temperatures. Here, we demonstrate inverted perovskite solar cells, in which the decomposition of the perovskite is significantly mitigated even at elevated temperatures. Specifically, we introduce a bilayered electron-extraction interlayer consisting of aluminium-doped zinc oxide and tin oxide. We evidence tin oxide grown by atomic layer deposition does form an outstandingly dense gas permeation barrier that effectively hinders the ingress of moisture towards the perovskite and—more importantly—it prevents the egress of decomposition products of the perovskite. Thereby, the overall decomposition of the perovskite is significantly suppressed, leading to an outstanding device stability.

Highly Efficient and Stable Semi‐Transparent p‐i‐n Planar Perovskite Solar Cells by Atmospheric Pressure Spatial Atomic Layer Deposited ZnO

“…Table shows the comparison of the photovoltaic parameters calculated from the backward JV curves of the fresh perovskite solar cells and the one stressed at 65 °C in N 2 environment after 1500 h. No degradation in the photovoltaic performance can be observed, with the average values that remain within the standard deviation. Our results are in line with the trend observed in literature using ALD SnO 2 layers and similar stress conditions . If we consider the hero cell, a slight improvement in the V OC and decrease in the J SC are observed for the aged device, which might be related to interface and/or bulk perovskite modifications due to the thermal budget applied to the perovskite device.…”

“…Despite the encouraging thermal stability for this specific PSC stack, further future activities will be necessary to fulfill the more demanding accelerating testing conditions required to evaluate the lifetime of a photovoltaic technology. Particularly, we will focus on i) different perovskite formulations, in the attempt to remove the more volatile and acidic MA component; and ii) the control of the interfaces, in particular the NiO NPs/perovskite. It has been reported in literature that the perovskite formation in the first nm is dependent on the metal oxide adopted as transport layer, with significant consequences on the carrier extraction and recombination mechanisms .…”

SnO2‐Based Perovskite Solar Cells: Configuration Design and Performance Improvement

“…Organic semiconductor materials have a much higher cost compared with inorganic semiconductor materials as well. So a lot of inorganic semiconductors were introduced to PSCs based on inverted structure . The ideal inorganic N‐type semiconductor materials includes TiO 2 , SnO 2 , ZnO, etc .…”

“…So a lot of inorganic semiconductors were introduced to PSCs based on inverted structure . The ideal inorganic N‐type semiconductor materials includes TiO 2 , SnO 2 , ZnO, etc . Nevertheless, the above inorganic materials as the electron transport layer often need high‐temperature sintering to form the ideal crystallization, which is not compatible with the fabrication of PSCs.…”

Crystalline Clear or Not: Beneficial and Harmful Effects of Water in Perovskite Solar Cells

“…[10,34,35,36] A wide amount of literature has been reported relating different methods through which to include water directly during the perovskite crystallization. However, it should be remarked that the highest PCEs are always obtained under completely dry environmental conditions, needing encapsulation techniques as an ally factor to enhance the long-term stability under real operation conditions.…”