Nonprecious Copper‐Based Transparent Top Electrode via Seed Layer–Assisted Thermal Evaporation for High‐Performance Semitransparent n‐i‐p Perovskite Solar Cells

Abstract

Semitransparent perovskite solar cells (ST‐PSCs) are highly attractive for applications in building‐integrated photovoltaics as well as in multijunction tandem devices. To fabricate high‐performance ST‐PSCs, suitable transparent top electrodes are strongly needed. Dielectric/metal/dielectric (DMD) multilayer structures have been shown to be promising candidates, though generally based on high‐value metals such as gold or silver, the latter causing also stability issues by reacting with perovskite. Here, a novel DMD transparent electrode based on nonprecious, less‐reactive copper is developed via thermal evaporation and used as a top anode in the fabrication of high‐performance semitransparent n‐i‐p perovskite solar cells, the best device yielding a power conversion efficiency as high as 12.5%. The DMD architecture consists of a gold‐seeded Cu thin film sandwiched between two MoO x dielectric layers. It is demonstrated that Cu self‐aggregation and diffusion into MoOx can be substantially limited by introducing an ultrathin (1.5 nm) Au seed layer, and conductive Cu films as thin as 9.5 nm can be achieved. A fine tuning of the perovskite layer thickness is also carried out to further enhance the device transparency up to a maximum average visible transmittance approaching 25%.

Recent Progress on Advanced Optical Structures for Emerging Photovoltaics and Photodetectors

“…By sandwiching a thin metal film between dielectric layers, decent electrical and optical properties can be achieved. [ 73,74,117,124 ]…”

“…The DMD structures in ST‐PSCs have been similar to those in ST‐OPVs. [ 33,45,48,49,73,74,78,79,117–122 ] For example, Hanmandlu et al introduced a 2,9‐dimethyl‐4,7‐diphenyl‐1,10‐phenanthroline (BCP)/Ag/MoO 3 transparent electrode for bifacial PSCs (Figure 2d). [ 79 ] In addition to providing a high dielectric constant, the BCP also functioned as a diffusion buffer layer between the electron transport layer (ETL) and the Ag electrode.…”

“…Plot of PCE with respect to AVT for ST‐OPVs and ST‐PSCs reported in the literature. [ 1,9–12,15,17,18,20–22,24,33–110 ] …”

Tackling Performance Challenges in Organic Photovoltaics: An Overview about Compatibilizers

“…Nowadays, third-generation Photovoltaics (PVs), including Organic Solar Cells (OSCs) [1][2][3], Dye-Sensitized Solar Cells (DSSCs) [4][5][6], and Perovskite Solar Cells (PSCs) [7][8][9], are making inroads, showing great potential to overcome some of the limitations of today's applied PV technologies, and opening the door to novel, unconventional PV applications. In particular, the exponential growth in the number of investigations on the topic of Organic Photovoltaics (OPVs) [10,11] has produced a tangible evolution of these promising devices [12].…”

Synergies and compromises between charge and energy transfers in three-component organic solar cells

“…[1][2][3] In the last few years, flexible and semitransparent OSCs have aroused by far the most interest for their promising applications in wearable energy resources, building-integrated photovoltaics as windows or skylights where it is difficult to install conventional solar cells, or in new applications such as multi-junction solar photovoltaics. 4,5 In addition, the employment of plastic substrates allows for the development of flexible, portable and biocompatible devices, also implementable on curved surfaces and on tissues. However, when OSCs are realized on a plastic substrate instead of glass, PCE values further decrease due to the higher surface resistivity of the electrode on the substrate and the lower light transparency of the plastic.…”