Perovskite Solar Cells with All‐Inkjet‐Printed Absorber and Charge Transport Layers

Abstract

One of the key challenges of perovskite photovoltaics is the scalable fabrication of high‐efficiency perovskite solar cells (PSCs). Not only the scalable deposition of high‐quality perovskite thin‐films itself, but also the adjacent charge extraction layers is pivotal. In this work, PSCs based on all‐inkjet‐printed absorber and extraction layers are presented, allowing for a scalable and material‐efficient deposition. The inkjet‐printed PSCs are of p–i–n‐architecture with a precursor‐based nickel oxide hole‐transport layer, a high‐quality inkjet‐printed triple‐cation (methylammonium, formamidinium, and cesium) perovskite absorber layer and a double layer electron‐transport layer of phenyl‐C61‐butyric acid methyl ester and bathocuproine. The ink properties, inkjet parameters, and annealing procedure are optimized for each layer. PSCs with such inkjet‐printed absorber and charge carrier extraction layers demonstrate an efficiency of >17% with low hysteresis. Although printed in ambient atmosphere, the devices show excellent short‐term stability (40 h) even under elevated temperature (85 °C). These results are a promising next step on the way to fully inkjet‐printed perovskite solar cells, including both electrodes as well.

A Review on Printed Electronics: Fabrication Methods, Inks, Substrates, Applications and Environmental Impacts

“…For the printable solar cells, various photoactive materials have been implemented in the literature including hybrid organic-inorganic materials like perovskites and organic conjugated polymer blends such as poly(3-hexylthiophene) (P3HT) (as being donor) and [6,6]-phenyl C61-butyric acid methylester (PCBM) (as being acceptor) [111][112][113][114]. Lab-scale investigations showed that printed perovskite solar cells can reach up to PCE values comparable with those of silicon solar cells, e.g., 16.6% PCE by Zhang et al [115], 17.2% PCE by Schackmar et al [116], 17.74% PCE by Li et al [117], stabilized PCE of 18.5% PCE by Eggers et al [118] and 19.6% by Li et al [119]. In addition to these developments, the printed organic cells developed by Liu et al [120] achieved 15% PCE.…”

Gas flow-assisted vacuum drying: identification of a novel process for attaining high-quality perovskite films

“…Especially vacuum drying was established for inkjet-printed layers and it is the most common protocol to produce highly efficient solar cells by crystallizing the wet film at a pressure between 10 À2 and 10 2 mbar. [12][13][14][15] Based on this effort, power conversion efficiencies (PCE) of close to 20% for partially printed devices, 15,16 and more than 17% for fully inkjet-printed solar cells, have been achieved up till now. 14 Furthermore, vacuum drying has been successfully used for other scalable methods, such as blade-coating, 17,18 spray-coating, 19 as well as for spin-coated films.…”

“…[12][13][14][15] Based on this effort, power conversion efficiencies (PCE) of close to 20% for partially printed devices, 15,16 and more than 17% for fully inkjet-printed solar cells, have been achieved up till now. 14 Furthermore, vacuum drying has been successfully used for other scalable methods, such as blade-coating, 17,18 spray-coating, 19 as well as for spin-coated films. 10,20 Regardless of these successes, a detailed review of the formation of MHPs with the vacuum drying process has been lacking in the literature.…”

Large-area perovskite films for PV applications: A perspective from nucleation and crystallization

“…On the other hand, the conventional spin coating method, typically used for small cell fabrication has its challenges when applied for large-area (>1 cm 2 ) fabrication, such as poor uniformity, solution wastage, low throughput. To overcome these limitations, various techniques have been developed, including slotdie coating [13][14][15][16][17][18], spray coating [19][20][21][22], inkjet printing [23,24], blade coating [25][26][27][28]. However, technical problems, e.g.…”