40.1% Record Low‐Light Solar‐Cell Efficiency by Holistic Trap‐Passivation using Micrometer‐Thick Perovskite Film

Abstract

Perovskite solar cells exhibit not only high efficiency under full AM1.5 sunlight, but also have great potential for applications in low‐light environments, such as indoors, cloudy conditions, early morning, late evening, etc. Unfortunately, their performance still suffers from severe trap‐induced nonradiative recombination, particularly under low‐light conditions. Here, a holistic passivation strategy is developed to reduce traps both on the surface and in the bulk of micrometer‐thick perovskite film, leading to a record efficiency of 40.1% under 301.6 µW cm−2 warm light‐emitting diode (LED) light for low‐light solar‐cell applications. The involvement of guanidinium into the perovskite bulk film and 2‐(4‐methoxyphenyl)ethylamine hydrobromide (CH3O‐PEABr) passivation on the perovskite surface synergistically suppresses the trap states. The charge carrier lifetimes of the perovskite film increase by tenfold and fivefold to 981 ns and 8.02 µs at the crystal surface and in its bulk, respectively. The decreased nonradiative recombination loss translates to a high open‐circuit voltage (Voc) of 1.00 V, a high short‐circuit current (Jsc) of 152.10 µA cm−2, and a fill factor (FF) of 79.52%. Note that this performance also stands as the highest among all photovoltaics measured under indoor light illumination. This work of trap passivation for micrometer‐thick perovskite film paves a way for high‐performance, self‐powered IoT devices.

Perovskite indoor photovoltaics: opportunity and challenges

“…Some groups have evaluated the manufacturing cost of perovskite modules with different geometries and have proposed related estimates of LCOE. 118,174,175 Han et al concluded that perovskite photovoltaic modules could be produced with simplified module geometry at an ultra-cost of $30–41 per square meter (excluding back-sealing glass, junction boxes, or wires). According to their assumptions, the LCOE value can be as low as 3.5–4.9 cents per kilowatt per hour, which is much lower than the cost of fossil fuel.…”

“… 115 They believed that PSCs could play a role as a cost leader in the PV field if the key remaining issues can be resolved. 118 Furthermore, this estimated cost will be further reduced with large-area processes ( e.g. , roll-to-roll (R2R) and screen printing), low-cost transport layers, or electrode materials that are widely used in PIPV.…”

Highly Efficient and Stable CsPbTh3 (Th = I, Br, Cl) Perovskite Solar Cells by Combinational Passivation Strategy

“…The black phases of CsPbI 3 have aroused widespread attention in the photovoltaics community due to its exceptional photovoltaic properties such as higher efficiency, excellent chemical and thermal stability, which act as a potential candidate for solar cells. [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ] In recent years, the power conversion efficiency (PCE) of CsPbI 3 perovskite solar cells (PSCs) climbed rapidly from 2.9% first reported by Snaith and co‐workers to 20.8% by Liu and co‐workers, and the efficiency gap between the CsPbI 3 and organic–inorganic hybrid PSCs is further reduced. [ 8 , 9 , 10 , 11 , 12 ] Furthermore, CsPbI 3 has a suitable bandgap (≈1.70 eV) and can be used as the top cell of tandem photovoltaic cells.…”

Rational Surface‐Defect Control via Designed Passivation for High‐Efficiency Inorganic Perovskite Solar Cells

“…Perovskite solar cells (PSCs), as one of the most promising photovoltaic technologies in the past decade, have gained considerable attention worldwide. [1][2][3][4][5] Despite the record power conversion efficiency (PCE) of 25.5 % announced in 2021, [6] the widely adopted metal halide organic-inorganic hybrid perovskites as active materials contain organic components (e.g. methylammonium (MA)), whose high volatility would threaten the long-term operational stability of devices.…”