Comparison of the Al back contact deposited by sputtering, e-beam, or thermal evaporation for inverted perovskite solar cells

Abstract

In this work, we present inverted perovskite solar cells with Al top electrodes, which were deposited by three different methods. Besides the widely used thermal evaporation of Al, we also used the industrially important high deposition rate processes sputtering and electron beam evaporation for aluminium electrodes and examined the influence of the deposition method on the solar cell performance. The current-voltage characteristics of as grown solar cells with sputtered and e-beam Al electrode show an s-shape due to damage done to the organic electronic transport layers (ETL) during Al deposition. It can be cured by a short annealing step at a moderate temperature so that fill factors >60% and power conversion efficiencies of almost 12% with negligible hysteresis can be achieved. While solar cells with thermally evaporated Al electrode do not show an s-shape, they also exhibit a clear improvement after a short annealing step. In addition, we varied the thickness of the ETL consisting of a double layer ([6,6]-Phenyl-C61-butyric acid methyl ester and bathocuproine) and investigated the influence on the solar cell parameters for the three different Al deposition methods, which showed distinct dependencies on ETL thickness.

The Role of SnF2 Additive on Interface Formation in All Lead‐Free FASnI3 Perovskite Solar Cells

“…However, such annealing conditions have widely been used in the past to make stable PEDOT:PSS layers in various types of solar cells. [ 38–45 ]…”

“…However, such annealing conditions have widely been used in the past to make stable PEDOT:PSS layers in various types of solar cells. [38][39][40][41][42][43][44][45] To investigate whether or not the formation of a SnS interlayer is limited to pure Sn-based perovskites or eventually also occurs for mixed (Pb/Sn) perovskites (where SnF 2 is also frequently added to suppress oxidation and to improve film morphology), additional HAXPES measurements were performed on a Pb-containing semi-finished device. More precisely, a FA 0.75 MA 0.25 (Pb 0.5 Sn 0.5 )I 3 film with thickness ≈100 nm (comprising the same SnF 2 molar ratio related to SnI 2 in the precursor solution as before) was deposited on PEDOT:PSS and subsequently analyzed in situ in the HAXPES-lab instrument.…”

Integrating Flexible Ultralight 3D Ni Micromesh Current Collector with NiCo Bimetallic Hydroxide for Smart Hybrid Supercapacitors

“…Also, different from the magnetron sputtering, thermal evaporation, and electron beam deposition techniques, electrodeposition is able to avoid the high temperature and vacuum environment, ensuring the formation of uniform metal films. [ 12 ] Besides, this process is cost‐effective since the conductive substrate and the electrodeposition bath can be recycled, which prominently reduces costs and increases productivity.…”

High-Efficiency Perovskite Solar Cells with Sputtered Metal Contacts

“…27−29 The lower performance is caused by highly energetic particles that bombard the PSC during deposition and damage the underlying organic hole transport layer (HTL). 4 This damage from the plasma can be caused by (i) the decomposition of organic layers creating interfacial defects; 30,31 (ii) the molecular order of the HTL being disrupted to create a charge extraction barrier; 27,32,33 and (iii) the diffusion of metal atoms into the HTL suppressing the charge extraction. 17,34,35 The damage caused by sputtering can be suppressed by an interfacial buffer layer.…”

“…In general, PCEs for sputtered devices are below 15%, which is much lower than the >20% PCEs common to thermally evaporated devices. − The lower performance is caused by highly energetic particles that bombard the PSC during deposition and damage the underlying organic hole transport layer (HTL) . This damage from the plasma can be caused by (i) the decomposition of organic layers creating interfacial defects; , (ii) the molecular order of the HTL being disrupted to create a charge extraction barrier; ,, and (iii) the diffusion of metal atoms into the HTL suppressing the charge extraction. ,, The damage caused by sputtering can be suppressed by an interfacial buffer layer. Thermally evaporated MoO 3 , thermally evaporated Au, and spin-cast ZnO nanoparticle interlayers positioned between the HTL and the sputtered metal contact have all been used to produce devices with efficiencies up to 16.6%.…”