Low-loss contacts on textured substrates for inverted perovskite solar cells

• Published in: Nature (London) Vol. 624; no. 7991; pp. 289 - 294
• Main Authors: Park, So Min, Wei, Mingyang, Lempesis, Nikolaos, Yu, Wenjin, Hossain, Tareq, Agosta, Lorenzo, Carnevali, Virginia, Atapattu, Harindi R., Serles, Peter, Eickemeyer, Felix T., Shin, Heejong, Vafaie, Maral, Choi, Deokjae, Darabi, Kasra, Jung, Eui Dae, Yang, Yi, Kim, Da Bin, Zakeeruddin, Shaik M., Chen, Bin, Amassian, Aram, Filleter, Tobin, Kanatzidis, Mercouri G., Graham, Kenneth R., Xiao, Lixin, Rothlisberger, Ursula, Grätzel, Michael, Sargent, Edward H.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 14.12.2023; Nature Publishing Group
• Subjects: 119/118; 140/125; 140/146; 639/301/299/946; 639/4077/909/4101/4096/946; Acids; Adsorbents; Adsorption; Chemical bonds; Efficiency; Energy conversion efficiency; Humanities and Social Sciences; Maximum power tracking; Molecular dynamics; multidisciplinary; Optoelectronic devices; Perovskites; Phosphonic acids; Photoelectric effect; Photovoltaic cells; Relative humidity; Room temperature; Science; Science (multidisciplinary); Self-assembled monolayers; Self-assembly; Simulation; Solar cells; Spectrum analysis; Substrates
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/s41586-023-06745-7

Inverted perovskite solar cells (PSCs) promise enhanced operating stability compared to their normal-structure counterparts 1 – 3 . To improve efficiency further, it is crucial to combine effective light management with low interfacial losses 4 , 5 . Here we develop a conformal self-assembled monolayer (SAM) as the hole-selective contact on light-managing textured substrates. Molecular dynamics simulations indicate that cluster formation during phosphonic acid adsorption leads to incomplete SAM coverage. We devise a co-adsorbent strategy that disassembles high-order clusters, thus homogenizing the distribution of phosphonic acid molecules, and thereby minimizing interfacial recombination and improving electronic structures. We report a laboratory-measured power conversion efficiency (PCE) of 25.3% and a certified quasi-steady-state PCE of 24.8% for inverted PSCs, with a photocurrent approaching 95% of the Shockley–Queisser maximum. An encapsulated device having a PCE of 24.6% at room temperature retains 95% of its peak performance when stressed at 65 °C and 50% relative humidity following more than 1,000 h of maximum power point tracking under 1 sun illumination. This represents one of the most stable PSCs subjected to accelerated ageing: achieved with a PCE surpassing 24%. The engineering of phosphonic acid adsorption on textured substrates offers a promising avenue for efficient and stable PSCs. It is also anticipated to benefit other optoelectronic devices that require light management. A co-adsorbent is used to achieve a uniform self-assembled phosphonic acid monolayer on a textured substrate, leading to more efficient inverted perovskite solar cells.