We report on the fabrication of highly efficient, semitransparent bulk heterojunction solar cells comprising poly[[9-(1-octylnonyl)-9h-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl] (PCDTBT) blended with [6,6]-phenyl-C71-butyric acid methyl (PC71BM) esters as active layer. As semitransparent cathode sputtered aluminum doped ZnO was used in combination with a sputter damage preventing, thin (8 nm) TiOx layer processed from solution and a sputtered aluminum interlayer (ALI). The short circuit current improves for thicker ALIs due to increased reflectance at the cathode leading to average efficiencies of 4.0% for semitransparent solar cells. Comparable results (3.9%) were achieved for devices comprising thick absorbers and thin ALIs.

Lab-scale perovskite solar cells (PSCs) have recently reached power conversion efficiencies (PCEs) of up to 25.2 %. However, a reliable transfer of solution processing from spin coating to scalable printing techniques and a homogeneous deposition on large substrate sizes is challenging also caused by dewetting of the perovskite precursor solution on highly hydrophobic subjacent materials. In this work, we report the utilization of blade coated non-conductive silicon oxide

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Perovskite solar cells (PSCs) have recently gained power conversion efficiencies (PCEs) of up to 25.5% on lab-scale nearly exclusively processed from precursor solutions involving harmful and polluting solvents like dimethylformamide (DMF). However, solution processing of green and environmentally safe solvents such as dimethyl sulfoxide (DMSO) via scalable printing is 2 challenging mainly caused by two reasons: firstly pronounced precursor solution dewetting on the subjacent layer and secondly its complex quenching process. In this work, we report on one-step blade coating of inverted (p-i-n) double-cation PSCs using solely DMSO at low processing temperatures. To avoid dewetting of the DMSO-based solution on the hydrophobic hole transport layer (HTL) and to realize adequate quenching, a blade coated wetting agent of silicon oxide nanoparticles at the HTL/perovskite interface and gas stream-assisted drying is applied, respectively. Trends in absorber grain size, morphology, crystallinity and elemental composition of samples from both toxic and green solvent concepts are compared revealing analogous findings.Consequently, PSCs blade coated from DMSO achieve PCEs of up to 16.7% on a 0.24 cm 2 active area comparable to the ones from a DMF:DMSO mixture (16.9%) and thus demonstrating that using toxic DMF is unnecessary. This represents an important step for bringing PSCs solution processed from environmentally friendly precursor solvents closer to industrial implementation.

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.