Self‐Encapsulating Thermostable and Air‐Resilient Semitransparent Perovskite Solar Cells

Abstract

Semitransparent perovskite solar cells (PSCs) are of interest for application in tandem solar cells and building-integrated photovoltaics. Unfortunately, several perovskites decompose when exposed to moisture or elevated temperatures. Concomitantly, metal electrodes can be degraded by the corrosive decomposition products of the perovskite. This is even the more problematic for semitransparent PSCs, in which the semitransparent top electrode is based on ultrathin metal films. Here, we demonstrate outstandingly robust PSCs with semitransparent top electrodes, where an ultrathin Ag layer is sandwiched between SnO x grown by low-temperature atomic layer deposition. The SnO x forms an electrically conductive permeation barrier, which protects both the perovskite and the ultrathin silver electrode against the detrimental impact of moisture. At the same time, the SnO x cladding layer underneath the ultra-thin Ag layer shields the metal against corrosive halide compounds leaking out of the perovskite. Our semitransparent PSCs show an efficiency higher than 11% along with about 70% average transmittance in the near-infrared region (λ > 800 nm) and an average transmittance of 29% for λ = 400-900 nm. The devices reveal an astonishing stability over more than 4500 hours regardless if they are exposed to ambient atmosphere or to elevated temperatures.

Emerging Novel Metal Electrodes for Photovoltaic Applications

“…Owing to the instability of the perovskite film and the diffusion of ion under electrical field, the decomposed halides will reach the metal transparent electrode and induce the degradation of the electrode. The insertion of the SnO x layer by atomic layer deposition (ALD) or the Au film through evaporation between the Ag NW (or ultrathin Ag film) based electrode and the perovskite film has demonstrated to be a barrier for inhibiting the immigration of halides to metal surface . Zhao et al had demonstrated the semitransparent PVSCs with the top transparent electrode of SnO x /Ag/SnO x that exhibits extraordinary stability over more than 4500 h .…”

“…The insertion of the SnO x layer by atomic layer deposition (ALD) or the Au film through evaporation between the Ag NW (or ultrathin Ag film) based electrode and the perovskite film has demonstrated to be a barrier for inhibiting the immigration of halides to metal surface . Zhao et al had demonstrated the semitransparent PVSCs with the top transparent electrode of SnO x /Ag/SnO x that exhibits extraordinary stability over more than 4500 h . Such compact SnO x layer on the top of device can also act as the encapsulated layer to protect the perovskite film from the attack by species in the outer environment, which is another important reason for the excellent stability performance of the device.…”

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

“…In order to adopt the perovskite solar cell as top device, the conventional metal electrode used in the stand‐alone perovskite solar cell needs to be replaced with a semi‐transparent contact serving as collecting electrode, but also enabling the near‐infrared light to reach the bottom cell. Several approaches have been already explored, such as the use of conductive oxides (TCOs), dielectric metal dielectric (DMD), ultrathin metals, and silver nanowires . Among all of them, TCOs deposited via sputtering technique are still considered the best candidate due to the high transmittance in the visible and near infrared region spectra, in combination with the excellent electrical conductivity.…”

“…Thermally evaporated MoO X or WoO X have been deposited on top of the spiro‐OMeTAD in the mesoporous TiO 2 based architecture in order to prevent the damages on the organic hole transport layer . In the case of the p‐i‐n configuration, the best results have been achieved using atomic layer deposition (ALD), fabricating a n‐type metal oxide buffer layer . ALD is acknowledged to provide very dense, uniform and conformal layers over large areas in a temperature range compatible with the sensitive materials used in the PSC devices.…”

All‐Oxide MoOx/SnOx Charge Recombination Interconnects for Inverted Organic Tandem Solar Cells

“…[18] Recently, SnO x has also been considered as EEL for solar cells based on hybrid perovskites with improved efficiency and long-term stability. [47][48][49][50] Initially, we have prepared single junction reference devices with a thickness of the photoactive layers identical to that of the sub-cells in the tandem devices. The optimum thickness of the active layers for current matching has been determined by an optical simulation taking into account the absorption characteristics of the photoactive layers in the tandem cell and the external quantum efficiency (EQE) of the single junction devices ( Figure S1, Supporting Information).…”