Triple-junction solar cells with improved carrier and photon management
Article Date: 17 March 2026
Article URL: https://www.nature.com/articles/s41586-026-10385-y
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Summary
This Nature paper reports advances that address two major bottlenecks in perovskite–silicon triple-junction photovoltaics: low open-circuit voltage in the wide-bandgap top cell and insufficient photocurrent in the middle cell. The team introduced a non-volatile additive, 4-hydroxybenzylamine, to control wide-bandgap perovskite crystallisation and passivate defects, raising VOC (up to 1.405 V) and improving stability. A three-step deposition method produced thick, low-bandgap perovskite absorbers with preserved microstructure and better electron extraction. Low-refractive-index SiOx nanoparticles placed in the textured silicon front valleys act as an optical middle-reflector, increasing light absorption in the middle cell. Combined in 1 cm2 perovskite–perovskite–silicon devices, these measures yielded a certified efficiency of 30.02%.
Key Points
- 4-hydroxybenzylamine additive regulates wide-bandgap perovskite crystallisation and passivates defects, suppressing non-radiative recombination.
- Improved energy-level alignment and defect passivation produced open-circuit voltages up to 1.405 V and enhanced device stability.
- A three-step deposition strategy enabled thick, low-bandgap middle-cell absorbers while maintaining microstructural integrity and electron extraction.
- Low-refractive-index SiOx nanoparticles in silicon front valleys act as an optical middle-reflector to boost middle-cell absorption.
- Integrated 1 cm2 perovskite–perovskite–silicon triple-junction devices reached a certified 30.02% efficiency.
- Work combines carrier (defect/passivation) and photon (optical management) strategies to push multi-junction performance.
Content summary
The authors systematically tackle carrier and photon management in a perovskite–perovskite–silicon stack. For the top wide-bandgap cell they use a non-volatile additive to guide crystal orientation and reduce recombination; for the middle low-bandgap cell they develop a layered deposition process that allows thicker absorbers without sacrificing charge transport. Optically, SiOx nanoparticle placement on the textured silicon surface functions as an internal reflector to redirect light into the middle perovskite. The combined electrical and optical improvements are validated on 1 cm2 devices and independently certified at 30.02% efficiency.
Context and relevance
This study is timely for groups pursuing tandem and multijunction photovoltaics: it shows practical pathways to overcome real device-level limits (VOC loss, current matching) rather than incremental material tweaks. Achieving a certified >30% on a perovskite–perovskite–silicon stack demonstrates that careful materials, processing and optical engineering together can push tandems towards commercially interesting efficiencies. The approaches are relevant to scale-up, stability research and optical design in next-generation PV stacks.
Author style
Punchy: the paper reads like a deliberate engineering playbook — identify the two weakest links (top-cell VOC and middle-cell current), then fix them with targeted chemistry, processing and optics. If you work in tandem PV or device integration, this is not just interesting — it’s directly useful. The results are substantial enough to warrant a close read of methods and supplementary data.
Why should I read this?
Short version: if you care about squeezing more percent points out of solar tech, this one’s for you. It shows practical fixes that actually move certified numbers — not just model curves. Great if you want ideas for materials tweaks, deposition tricks or clever light-management that translate to real devices.