Two‐Terminal Perovskite‐Based Tandem Solar Cells for Energy Conversion and Storage

Abstract

Nowadays, the power conversion efficiency (PCE) of single-junction solar cells is almost approaching the theoretical ceiling of 31-33% according to Shockley-Queisser (S-Q) single-junction efficiency limitation. [2] However, the output voltage of the most efficient single-junction solar cells such as GaAs is about 1 V, which is insufficient for practical application to subsequently drive energy storage/utilization devices. Fortunately, by connecting multiple absorber layers to fabricate the tandem solar cells, the output voltage could be significantly increased as well as the PCE. According to S-Q analysis, the theoretical efficiencies of two-junction and three-junction solar cells could be as high as 42% and 49%, respectively. [3] Importantly, the output voltage of the tandem solar cells would be nearly doubled or tripled correspondingly. As an example, the open-circuit voltage (V OC ) of single line silicon solar cells is only about 0.6 V, which could be increased up to 1.21 V by stacking CdSe on the top of silicon. [4] Recently, with the rapid development of high-voltage perovskite solar cells (PSCs), the V OC of the tandem solar cells is remarkably improved. Typically, the highest V OC can reach up to 2.3 V for two-junction tandem solar cells, consisting of two CH 3 NH 3 PbI 3 (MAPbI 3 ) subcells. [5] Though higher voltage could be achieved by adding more junctions, such as 3.21 V in three-junction tandem cells, [6] 4.227 V for four-junction tandem cells, [7] 4.40 V for five-junction tandem cells, [8] and calculated 5.15 V for six-junction tandem cells, [9] yet the cost and technological requirements would increase exponentially. It is noted that although solar modules with simple serial connected design can also provide high voltage, the light management is still the same as single-junction cells, which could never beyond S-Q limitation. Tandem solar cells could provide a possibility for breaking physical limitation of traditional single-junction solar cells. Besides, tandem solar cells could also be basic unit for solar modules to obtain higher efficiency.As shown in Figure 1, tandem solar cells could deliver high PCE and V OC by segmented light adsorption. The PCE of solar cells is determined mainly by two processes: light absorption and carriers separation/collection. Usually, short-circuit current density (J SC ) would be lower than theory limit because of incomplete light absorption and sluggish collection of generated carriers, whereas a reduced Voc or fill factor (FF) reflectsThe organic-inorganic hybrid perovskite solar cells present a rapid improvement on power conversion efficiency from 3.8% to 25.5% in the past decades. Owing to the tuneable bandgaps, low-cost, and ease of fabrication, perovskites become ideal candidate materials for fabricating tandem solar cells, especially for efficient and high-voltage monolithic two-terminal devices. In this review, an overview of recent advances in various monolithic perovskitebased tandem solar cells with a focus on the key challenges is provided. Subsequent...

Thermodynamic modeling of a spectrum split perovskite/silicon solar cell hybridized with thermoelectric devices

“…The radiation and convective heat terms can be replaced with an equivalent heat quantity. Substituting Equation (18) into Equation (17) gives the expression in Equation ( 19)…”

“…The efficiency recorded by the hybrid bifacial solar cell was greater than the 29.43% Schockley-Quiesser limit for crystalline-based Silicon solar cells. He et al 10 17 noted that the high conversion efficiencies obtained from tandem perovskite/ Si solar cells were due to the advantages of perovskite materials such as their low cost, tunable bandgaps, and easy fabrication.…”

ZIF-derived frame-in-cage hybrids of ZnSe–CdSe embedded within a N-doped carbon matrix for efficient photothermal conversion of CO2 into fuel

“…1,2 The efficient conversion and storage of solar energy are significant ways to solve the problem of energy shortage. 3,4 Photocatalysis is based on the effective separation of photogenerated carriers on different semiconductors. 5,6 Although a variety of methods have been developed to improve the separation efficiency of photogenerated carriers, most of the solar energy absorbed by semiconductors is lost in the form of heat energy through the rapid recombination of light-generated carriers.…”

Two-dimensional InSb/GaAs- and InSb/InP-based tandem photovoltaic device with matched bandgap

“…14 Currently, Si/perovskite-based tandem PVs have been extensively studied. 15–17 Nevertheless, the stability of perovskite in association with the mobilities of Si and perovskite, 18,19 are yet unresolved issues. Thus, it is urgent to seek compatibility between E g and high charge mobility to acquire high-performance tandem PVs.…”