Synergic Interface and Optical Engineering for High‐Performance Semitransparent Polymer Solar Cells

Abstract

both the top and bottom electrodes. These semitransparent PSCs (ST-PSCs) could be used as power generating windows and aesthetic architectural glasses, which are considered as the most appealing photovoltaic product for building integrated photovoltaic applications. [12][13][14][15][16][17][18] However, unlike opaque PSCs, the overall performance of ST-PSCs depends not only on the PCE but also the average visible transmittance (AVT) and color rendering properties. [19] Therefore, the great challenge for ST-PSCs is to achieve high PCE yet with good AVT and color rendering properties.Optimization of both the PCE and AVT in ST-PSCs is inherently challenging as these two performance parameters are difficult to optimize at the same time. The ideal optical condition for ST-PSC can be reached when the light passes through the device is only absorbed by the active layer but not the other layers such as the transparent electrodes and the interlayers, which allows the maximal amount of light transmitted through the devices. The ideal electronic condition for ST-PSC fulfilled if all the photons absorbed by the light harvesting layer can be dissociated and collected to generate photocurrent with internal quantum efficiency equal to 100%. [20] However, in real cases, the optical and electronic properties of the ST-PSCs are strongly affected by the choice of interlayers and transparent electrodes. For example, the interlayer not only can act as a charge selective layer to improve charge extraction in PSCs but also can act as an optical spacer that alters the optical field distribution within the device. [21] Depending on the choice of the transparent conductive material used for constructing the transparent electrode, it can be categorized as nonreflective or semireflective one. The latter case, which can be fabricated using ultrathin metal films (UTMFs) with the reflectance and transmittance depending on the thickness of the metal films, is of particular interest as it provides better flexibility in tuning the optical property of ST-PSCs. [22,23] However, the deposition of high quality and smooth UTMF, which is a prerequisite for achieving high transparency and conductivity, as top transparent conducting electrode for ST-PSCs is not straight forward and the film quality is strongly depending of the choice of underneath charge transport layer and deposition conditions. [24][25][26] In previous reports, tailored charge transport layers, such as a C 60 surfactant as electron transport layer (ETL) and MoS 2 as hole transport layer, had been In this study the thickness of the PTB7-Th:PC 71 BM bulk heterojunction (BHJ) film and the PF3N-2TNDI electron transport layer (ETL) is systematically tuned to achieve polymer solar cells (PSCs) with optimized power conversion efficiency (PCE) of over 9% when an ultrathin BHJ of 50 nm is used. Optical modeling suggests that the high PCE is attributed to the optical spacer effect from the ETL, which not only maximizes the optical field within the BHJ film but also facilitates the formation of a...

Solution‐Processable Conductive Organics via Anion‐Induced n‐Doping and Their Applications in Organic and Perovskite Solar Cells

“…These non‐fullerene interfacial materials are also effective ETLs for high‐performance OSCs and PVSCs due to their decent electron transporting capabilities, WF tunabilities, as well as solution processability. For instance, NDI‐based conjugated polymer surfactant reported by Huang et al, PNDIT‐F3N‐Br, exhibited self‐doping functionalities between Lewis base anion and NDI moieties, which can be processed through alcohol solvent, and obtained good performance with a broad range of ETL thickness for OSCs, and the doping effect between Lewis base anions and NDI moieties has also been verified by ESR experiments . PDI‐based surfactants also exhibited good conductivities for solar cell applications, which allow fabricating thick ETL layer for good performance .…”

“…www.advancedsciencenews.com www.mcp-journal.de for OSCs, [82,[95][96][97] and the doping effect between Lewis base anions and NDI moieties has also been verified by ESR experiments. [82] PDI-based surfactants also exhibited good conductivities for solar cell applications, which allow fabricating thick ETL layer for good performance.…”

“…Apart from fullerene‐based conductive interlayers, a series of non‐fullerene interfacial molecules and polymers (shown in Figure ) have been developed, such as perylene diimide (PDI) and naphthalene diimide (NDI) based n‐type semiconductors . These non‐fullerene interfacial materials are also effective ETLs for high‐performance OSCs and PVSCs due to their decent electron transporting capabilities, WF tunabilities, as well as solution processability.…”

“…Apart from fullerene-based conductive interlayers, a series of nonfullerene interfacial molecules and polymers (shown in Figure 5) have been developed, such as perylene diimide (PDI) and naphthalene diimide (NDI) based n-type semiconductors. [82,[95][96][97][98][99][100][101][102] These non-fullerene interfacial materials are also effective ETLs for high-performance OSCs and PVSCs due to their decent electron transporting capabilities, WF tunabilities, as well as solution processability. For instance, NDI-based conjugated polymer surfactant reported by Huang et al, PNDIT-F3N-Br, exhibited self-doping functionalities between Lewis base anion and NDI moieties, which can be processed through alcohol solvent, and obtained good performance with a broad range of ETL thickness Figure 3.…”

Solution‐Processable 2D α‐In2Se3 as an Efficient Hole Transport Layer for High‐Performance and Stable Polymer Solar Cells

“…The drastic enhancement of PCE is inseparable from interface engineering including the development of the hole transport layer (HTL). As a vital component of PSCs, HTL plays an important role in anode modification, hole transporting, electron blocking, bulk heterojunction (BHJ) morphology altering, etc . Great efforts have been devoted to develop more efficient and stable HTL materials to further improve the performance of PSCs.…”