Nicotinamide‐Modified PEDOT:PSS for High Performance Indoor and Outdoor Tin Perovskite Photovoltaics

Abstract

Tin perovskites are generally considered as promising candidates to solve the issue of toxicity for lead perovskites. However, the open‐circuit voltage (VOC) of tin perovskite solar cells is usually lower than expected. Herein, the hole‐transporting layer of PEDOT:PSS is treated with nicotinamide, and the tin perovskite active layer is deposited on the treated film to prepare a perovskite photovoltaic device. The fabricated device presented an increased VOC from 0.63 to 0.82 V, yielding an improved power conversion efficiency (PCE) increased from 4.77% to 8.28%. More importantly, under the weak light (1000 lux) irradiation of a simulated indoor light source, the device presented a PCE as high as 14.40%, which is the highest indoor efficiency for tin‐based perovskite photovoltaics reported so far. The promising indoor performance of tin perovskite photovoltaics paves a new way to fabricate eco‐friendly indoor photovoltaics by using lead‐free tin perovskites.

Nucleation and crystallization manipulations of tin halide perovskites for highly efficient solar cells

“…The PCE of KSCN-modified tin-perovskite devices increased to 11.17% and the highest indoor efficiency of 17.57% under 334.41 μW cm −2 was achieved. 111 In 2019, Chen et al introduced poly[tetraphenylethene 3,3′-(((2,2-diphenylethene-1,1-diyl)bis(4,1-phenylene))bis(oxy))bis( N , N -dimethylpropan-1-amine)tetraphenylethene] (PTN–Br) to form a bulk heterojunction film. 112 The π-conjugated PTN–Br could form Lewis adducts with tin to fill the grain boundaries and passivate the trap state.…”

Perovskite Photovoltaics for Artificial Light Harvesting

“…Later, the same group achieved an improved Sn-based PALC with a PCE of 14.4 % by modifying the work function of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PE-DOT:PSS) hole transport layer (HTL) with nicotinamide. [49] Cao and his colleagues [50] employed KSCN as a multifunctional interfacial material for achieving an optimized energy band alignment, a retarded tin oxidation and a facilitation of perovskite crystallization in Sn-based perovskite photovoltaics, and obtained a PCE of 17.57 % under 1062 lux illumination.…”

PEDOT:PSS/CuCl Composite Hole Transporting Layer for Enhancing the Performance of 2D Ruddlesden–Popper Perovskite Solar Cells

“…For instance, its work function (−5.1 eV) does not match with the valence band of the 2D RP perovskite layer (−5.4 eV). 11,12 In particular, the hygroscopic and acidic nature of PSS often contributes to some instability issues, such as oxidation of some metals or metal oxides, and detriment of some active materials with basic characteristics in 2D RP PSCs. 13−15 These problems greatly offset the benefit of using stable 2D RP perovskites as light absorbers.…”

“…8,16 Consequently, modifying PEDOT:PSS becomes an effective way to overcome these weaknesses but maintain the original advantages of PEDOT:PSS for fulfilling highly efficient and stable 2D RP PSCs. 12,17 Chemical doping of materials is a powerful method to elevate the electronic conductivity of HTLs by modulating the energy states and carrier concentration in semiconductors. Up to now, numerous attempts around chemical doping have been made to develop new types of n-type dopants, but quite limited research is accessible involved with p-type dopants.…”

“…Nevertheless, PEDOT:PSS shows some shortcomings. For instance, its work function (−5.1 eV) does not match with the valence band of the 2D RP perovskite layer (−5.4 eV). , In particular, the hygroscopic and acidic nature of PSS often contributes to some instability issues, such as oxidation of some metals or metal oxides, and detriment of some active materials with basic characteristics in 2D RP PSCs. − These problems greatly offset the benefit of using stable 2D RP perovskites as light absorbers. , Consequently, modifying PEDOT:PSS becomes an effective way to overcome these weaknesses but maintain the original advantages of PEDOT:PSS for fulfilling highly efficient and stable 2D RP PSCs. , …”