Fully Textured, Production‐Line Compatible Monolithic Perovskite/Silicon Tandem Solar Cells Approaching 29% Efficiency

Abstract

Perovskite/silicon tandem solar cells are promising avenues for achieving high‐performance photovoltaics with low costs. However, the highest certified efficiency of perovskite/silicon tandem devices based on economically matured silicon heterojunction technology (SHJ) with fully textured wafer is only 25.2% due to incompatibility between the limitation of fabrication technology which is not compatible with the production‐line silicon wafer. Here, a molecular‐level nanotechnology is developed by designing NiOx/2PACz ([2‐(9H‐carbazol‐9‐yl) ethyl]phosphonic acid) as an ultrathin hybrid hole transport layer (HTL) above indium tin oxide (ITO) recombination junction, to serve as a vital pivot for achieving a conformal deposition of high‐quality perovskite layer on top. The NiOx interlayer facilitates a uniform self‐assembly of 2PACz molecules onto the fully textured surface, thus avoiding direct contact between ITO and perovskite top‐cell for a minimal shunt loss. As a result of such interfacial engineering, the fully textured perovskite/silicon tandem cells obtain a certified efficiency of 28.84% on a 1.2‐cm2 masked area, which is the highest performance to date based on the fully textured, production‐line compatible SHJ. This work advances commercially promising photovoltaics with high performance and low costs by adopting a meticulously designed HTL/perovskite interface.

Minimizing the Ohmic Resistance of Wide‐Bandgap Perovskite for Semitransparent and Tandem Solar Cells

“…It is important to deposit uniform NiO x film with full coverage on the silicon bottom cells by sputtering method for high‐performance tandem solar cells. [ 47 ] We also found that the PCE of Si/PVK tandem device without NiO x is lower due to the poor FF (Figure S10 and Table S4, Supporting Information), which may be attributed to the imperfect contact between Si and PSC. Besides, we also fabricated tandem solar cells based on both PCBM and C 60 , and found that C 60 ‐based tandem devices showed better PCE, as shown in Figure S10, Supporting Information.…”

Next-generation applications for integrated perovskite solar cells

“…With a large market share of more than 90%, low fabrication cost, suitable bandgap, exceptional performance, and life span of over 20 years, Si solar cells are the most mature candidate to combine with PSCs in a tandem device. Indeed, the integration of PSCs with silicon cells to form tandem devices has provided a great opportunity to realize highefficiency PV systems 40,41 . One of the challenges in the development of perovskite/silicon tandem solar cells (PSTSCs) is the requirement for transparent and conductive electrodes to allow for the transmittance of the near-infrared (NIR) part of the incident light through the semitransparent perovskite top subcell to the bottom Si subcell.…”

Applications of vacuum vapor deposition for perovskite solar cells: A progress review

“…Evaporating a uniform lead halide skeleton followed by solution-processed ammonium salt penetration is a good way to build high-quality perovskite layers. Li et al reported a hybrid vapor-solution deposited p-i-n perovskite top cell on fully textured c-Si solar cell to construct conformal-grown monolithic tandem cells (Figure 3c) [44] . They coevaporated CsBr and PbI 2 on the textured substrate, followed by a spin-coating procedure of a mixture of FABr and FAI with a molar ratio of 1:6.98.…”

“…They also demonstrated the large-area scalability of the all-vacuum deposited PSCs with a device structure of ITO/spiro-mF/MAPbI 3 /PC 61 BM/ZnO/Ag. 2,2′, 7,7′ -tetra(N,N-di-tolyl)amino-9,9-spiro-bifluorene (Spiro-TTB) as another spiro-based derivative was also reported for thermal evaporation [44] . Vaynzof and her group obtained a PCE of 16.6% for fully-evaporated Cs 0.1 FA 0.9 PbI 2.9 Br 0.1 PSCs [52] .…”

“…Considering the low thermal tolerance of the underlying perovskite, ALD is an ideal method for depositing the buffer layer between the CTL and transparent electrode [65] . The most commonly-used ALD buffer layer is SnO 2 for top cells with a p-i-n structure, which can facilitate the charge transport and inhibit water penetration to improve stability without sacrificing the light transmittance [44,45] . To date, many reported efficient monolithic Si-perovskite tandem cells deposit an ALD-SnO 2 thin layer between the sputtered TCO and C 60 , and by now the efficiency has reached 31.25% [2] .…”