Nature study reports perovskite–silicon tandem cells sustain performance in extended damp‑heat testing

Nature on Wednesday published peer-reviewed results showing perovskite–silicon tandem solar cells that retained more than 95 percent of initial power after extended damp heat exposure. The work, led by Steve Albrecht at Helmholtz-Zentrum Berlin with Henry Snaith at the University of Oxford and Stefaan De Wolf at King Abdullah University of Science and Technology, reports certified efficiencies above 30 percent on 16 square centimeter devices using an industry-compatible encapsulation stack. The findings address a key barrier for tandems, which have struggled to meet long-duration stability criteria used for bankability.

Manufacturers in China and Europe are evaluating tandem pilot lines, and investors have demanded data that aligns with IEC 61215 stress protocols. Demonstrating retention under 85 degrees Celsius and 85 percent relative humidity for thousands of hours, under maximum power point tracking, moves perovskite tandems closer to qualification steps required by project financiers.

Methods and what was proved The team fabricated monolithic tandems that paired a textured silicon bottom cell with a wide bandgap perovskite top cell. The stack used nickel oxide and self-assembled monolayers for charge transport, transparent conductive oxides deposited by sputtering, and glass–glass encapsulation with polyolefin layers to mitigate moisture ingress.

Devices were run at one sun equivalent in climate chambers under 85 and 85 conditions with continuous electrical bias and periodic characterization. The study tracked electroluminescence, photoluminescence, and secondary ion mass spectrometry to monitor ion migration and halide segregation. The cells maintained efficiency within a narrow window, and failure analysis indicated that composition tuning and interfaces limited degradation pathways at elevated temperature and humidity.

What it does not show The results were obtained on cell areas below module scale and under accelerated conditions. The paper does not establish multi-year outdoor performance, manufacturing yield at gigawatt scale, or address lead containment strategies at the panel level. It also does not resolve throughput and cost questions for scalable perovskite deposition and tandem interconnection.

Implications for industry If extended damp heat retention at the cell level can be reproduced in minimodules, makers can advance to full IEC qualification and third-party reliability testing. That would clarify risk for early utility deployments and influence procurement strategies as established PV firms weigh tandem lines against incremental gains in TOPCon and heterojunction silicon.