Renewables
New classification proposed for UV degradation in TOPCon solar cells
Trina Solar researchers have proposed categorising ultraviolet-induced degradation in TOPCon solar cells into reversible and irreversible types to improve reliability testing.
Key points
- Researchers distinguish between reversible and irreversible ultraviolet-induced degradation.
- The categories align with upcoming International Electrotechnical Commission standards.
- Mitigation strategies focus on passivation improvements and hydrogen management.
What happened
Scientists from Chinese solar manufacturer Trina Solar have introduced a new classification system for ultraviolet-induced degradation (UVID) in tunnel oxide passivated contact (TOPCon) solar cells. According to pv magazine, the framework separates degradation into reversible (r-UVID) and irreversible (ir-UVID) forms to standardise testing and enhance long-term performance assessments.
The proposed categories align with recovery procedures in the developing International Electrotechnical Commission technical specification IEC TS 63624-1. Corresponding author Zhiwei Li stated that the framework establishes a common language for reliability testing, warranties, and project financing.
Why it matters
TOPCon solar cells exhibit pronounced metastability under ultraviolet exposure. While cells can experience performance losses during dark storage due to declining open-circuit voltage, field tests confirm that daily sunlight enables dynamic recovery through thermal annealing and light soaking.
The severity of degradation depends heavily on manufacturing factors, including the thickness of the aluminium oxide layer, hydrogen content, and capping layer choices. The research recommends higher ultraviolet exposure levels combined with standardised light-soaking recovery to accurately isolate permanent energy yield losses from temporary reductions.
What comes next
Improving front-side passivation remains central to mitigating module degradation. Researchers suggest optimising aluminium oxide thickness, employing atomic layer deposition, and utilising alternative capping materials such as silicon oxynitride.
Further investigations are required to address environmental stress combinations, establish equivalence criteria for ultraviolet aging light sources, and quantify ultraviolet-B radiation impacts. Targeted strategies for preventing permanent performance losses are also under development.
Original reporting
This article draws on the following reports. Read them in full on the publishers’ sites.
Context from CEII
Renewables are the fastest-growing part of the world’s energy system. The COP28 goal is to triple capacity by 2030, and solar mini-grids are the fastest route to power for millions of people without electricity.
27.8% of electricity in the world was renewable in 2021Countries in this story
Written by the CEII Desk, the Centre’s automated newsroom, from the reporting credited above and CEII’s own data. Facts are attributed to their sources; the publishers have not reviewed this article. Spotted an error? Tell our editors.
