Efficient bifacial monolithic perovskite/silicon tandem solar cells via bandgap engineering

Abstract

Bifacial monolithic perovskite/silicon tandem solar cells exploit albedo-the diffuse reflected light from the environment-to increase their performance above that of monofacial perovskite/silicon tandems. Here we report bifacial tandems with certified power conversion efficiencies >25% under monofacial AM1.5G 1 sun illumination that reach power-generation densities as high as ~26 mW cm -2 under outdoor testing. We investigated the perovskite bandgap required to attain optimized current matching under a variety of realistic illumination and albedo conditions. We then compared the properties of these bifacial tandems exposed to different albedos and provide energy yield calculations for two locations with different environmental conditions. Finally, we present a comparison of outdoor test fields of monofacial and bifacial perovskite/silicon tandems to demonstrate the added value of tandem bifaciality for locations with albedos of practical relevance.

Linked Nickel Oxide/Perovskite Interface Passivation for High‐Performance Textured Monolithic Tandem Solar Cells

“…[8] Alongside these properties, the availability of various fabrication techniques that are compatible with deposition on textured c-Si substrates, [2,9] has been critical toward the development of efficient perovskite/silicon tandem solar cells. [2,10] Key challenges that require sustained research efforts are device stability, [3] scaled processing, [9] and the fulfillment of the promise of perovskite/silicon tandems to yield PCEs well beyond 30%. [11] The lack of efficient hole-transport layers (HTLs) without significant parasitic absorption at the blue part of the solar spectrum (and that can be processed onto the perovskite films) has dictated to date the polarity of efficient perovskite/silicon toward p-i-n configurations, [12] where light enters the device from the n-side (i.e., electron collecting) of the perovskite topcell.…”

A Thienothiophene‐Based Cation Treatment Allows Semitransparent Perovskite Solar Cells with Improved Efficiency and Stability

“…Since we achieved exceptional stability with MoO x -containing solar cells, we also fabricated ST-PSCs with TTMAI-treated perovskite (ST-TT3DP) with an efficiency of 17.9% PCE, one of the highest efficiencies among ST-PSCs fabricated with formamidinium methylammonium (FAMA)-based perovskites. [43][44][45][46][47][48][49] The TTMAI treatment also enhanced the stability of ST-TT3DP significantly where after six weeks (>1000 h), the ST-TT3DP retained 87% of its initial efficiency, while the reference solar cell maintained only 69% of it. Considering the efficiency and stability aspects together, the results in this work constitute one of the best-performing ST-PSCs in the literature (Table S1, Supporting Information).…”

Electroplated Copper Metal Contacts on Perovskite Solar Cells

“…[26] Besides low contact resistivity ≤ 1 mΩ cm 2 and high adhesion %3 N mm À1 of the contacts on ITO, simultaneous Cu electroplating on both cell sides drives down the cost for this resist-free metallization [36] and could as well be adapted to bifacial tandem perovskite-SHJ devices, which were shown to be promising for reaching higher energy yield. [37] Copper electrodes were plated on the PSCs for the two scenarios without dissolution of the underlying FA 0.75 Cs 0.25 Pb(I 0.8 Br 0.2 ) 3 perovskite absorber, as shown in Figure 2. Indeed, next to the plated Cu fingers, the typical grain microstructure [38] of the complete underlying stack can be observed through the transparent Al 2 O 3 or even through the PVD Cu/Al stack.…”