A molecular photosensitizer achieves a Voc of 1.24 V enabling highly efficient and stable dye-sensitized solar cells with copper(II/I)-based electrolyte

Abstract

To develop photosensitizers with high open-circuit photovoltage (Voc) is a crucial strategy to enhance the power conversion efficiency (PCE) of co-sensitized solar cells. Here, we show a judiciously tailored organic photosensitizer, coded MS5, featuring the bulky donor N-(2’,4’-bis(dodecyloxy)-[1,1’-biphenyl]-4-yl)-2’,4’-bis(dodecyloxy)-N-phenyl-[1,1’-biphenyl]-4-amine and the electron acceptor 4-(benzo[c][1,2,5]thiadiazol-4-yl)benzoic acid. Employing MS5 with a copper (II/I) electrolyte enables a dye-sensitized solar cell (DSC) to achieve a strikingly high Voc of 1.24 V, with the Voc deficit as low as 130 mV and an ideality factor of merely 1.08. The co-sensitization of MS5 with the wider spectral-response dye XY1b produces a highly efficient and stable DSC with the PCE of 13.5% under standard AM1.5 G, 100 mW cm−2 solar radiation. Remarkably, the co-sensitized solar cell (active area of 2.8 cm2) presents a record PCE of 34.5% under ambient light, rendering it very attractive as an ambient light harvesting energy source for low power electronics.

Perovskite indoor photovoltaics: opportunity and challenges

“…94 Very recently, Grätzel et al reported the highest efficiency of 34.5% under 1000 lux for DSSCs with copper(II/I)-based electrolyte, indicating that this type of photovoltaics still occupies a leading position in the eld of IPVs. 95 In 2019, Liu et al summarized the PCE, V oc , and bandgap of various types of IPVs, such as Si thin-lm, perovskite, GaAs, InGaP, DSSCs, and OPVs based IPVs (Fig. 2c).…”

Stable Dye‐Sensitized Solar Cells Based on Copper(II/I) Redox Mediators Bearing a Pentadentate Ligand

“…The ever‐increasing energy demands combined with climate and environmental concerns have motivated our society to find alternative renewable energy sources [1, 2] . Dye‐sensitized solar cells (DSCs) have attracted widespread research attention as one of the most promising next‐generation solar cell technologies over the past three decades, because of their simplicity of fabrication, aesthetic design characteristics, and excellent performance especially for diffuse and low light applications [3–14] …”

Resolving electron injection from singlet fission-borne triplets into mesoporous transparent conducting oxides

“…Dye-sensitized solar cells (DSSCs), for example, combine wide band-gap metal-oxide semiconductors with molecular photosensitizers to generate electricity from sunlight; however, in the past 25 years, power conversion efficiencies (PCE) have increased only slightly from 10% in 1997 1 to 13.5% in 2021. 2 Organic chromophores devoid of rare metals have supplanted traditional dyes in the recent record devices, which may also offer the opportunity to exceed existing limits by multiplying excitons. 3,4 Singlet fission represents one opportunity for exciton multiplication, 3 and understanding of the process in various molecular chromophores has advanced significantly over the past decade.…”

“… 1 ) to 13.5% in 2021. 2 Utilizing chromophores with exciton multiplication potential, such as singlet fission (SF) dyes, offers an opportunity to exceed conventional PCE limits. 3,4 Understanding of SF in various molecular chromophores has advanced significantly over the past decade.…”