by Riko Seibo
Tokyo, Japan (SPX) Dec 17, 2025
Researchers at Chonnam Nationwide College within the Republic of Korea report {that a} nanometer scale germanium oxide layer can tackle a longstanding bottleneck in tin monosulfide skinny movie photo voltaic cells by enhancing the rear contact interface with the steel electrode. They targeted on tin monosulfide, or SnS, a non poisonous and low value absorber that makes use of earth plentiful parts and avoids indium, gallium, and tellurium whereas providing favorable optical and digital properties for daylight harvesting in idea. In observe, measured efficiencies have lagged theoretical predictions due to structural defects, parasitic reactions, and atomic diffusion on the interface the place SnS meets the again steel contact.
The crew led by Professor Jaeyeong Heo and Dr Rahul Kumar Yadav designed a tool structure that inserts an extremely skinny germanium oxide, or GeOx, interlayer between the molybdenum again contact and the SnS absorber. Their research, revealed on-line in Small on September 19 2025, describes how this interface engineering technique targets deep degree defects and undesirable chemical phases that type throughout excessive temperature processing of standard SnS cells.
To manufacture the GeOx layer, the researchers used a vapor transport deposition course of that first deposits a really skinny germanium movie after which depends on its pure oxidation to type a managed oxide with a thickness of about 7 nanometers. This method is appropriate with scalable, trade oriented skinny movie processing. “Regardless of its nanoscale thickness, this interlayer addresses a number of long-standing challenges without delay,” explains Prof. Heo. “It suppresses dangerous deep-level defects, blocks undesirable sodium diffusion, and prevents the formation of resistive molybdenum disulfide phases throughout high-temperature fabrication.”
By stabilizing the rear interface, the GeOx layer improves the microstructure of the SnS absorber, yielding bigger and extra uniform grains that facilitate cost transport. The authors report enhanced cost assortment and decrease electrical losses, which collectively increase the general gadget efficiency. In quantitative phrases, the ability conversion effectivity elevated from 3.71% in normal gadgets with out the interlayer to 4.81% when the optimized GeOx passivation was applied, one of many highest efficiencies reported for vapor deposited SnS primarily based photo voltaic cells.
The work additionally highlights broader implications of exact management over steel semiconductor interfaces past photovoltaic gadgets. The researchers be aware that comparable interface optimization can affect contact resistance and switching conduct in skinny movie transistors, vitality conversion efficiency in thermoelectric modules, cost switch and detection sensitivity in sensors, mechanical reliability in versatile electronics, and operation of photodetectors and reminiscence gadgets. “Throughout all these functions, mastering the steel/semiconductor interface stays central to advancing next-generation gadgets,” says Prof. Heo. “We imagine that this work will open new avenues for analysis, contributing to the event of superior photo voltaic cells and different key applied sciences.”
Associated Hyperlinks
Chonnam Nationwide College
All About Photo voltaic Power at SolarDaily.com
