Research team overcomes material challenges, providing a new path for high-efficiency LEDs

Silicon has long dominated the semiconductor materials race, but its "inherent defects" in the optoelectronic field have also limited its growth potential. Recently, researchers developed a new semiconductor material composed of germanium and tin, which exhibits superior light absorption and emission efficiency compared to silicon semiconductors and may become the next generation of high-performance semiconductors.

Silicon is the cornerstone of the modern electronics Industry; chips in most electronic products such as computers and mobile phones are primarily made of silicon and remain difficult to replace with other materials.

Although silicon possesses advantages such as technological maturity and low cost, its "indirect bandgap" characteristic results in a luminous efficacy far lower than that of direct bandgap materials (such as gallium arsenide GaAs). Consequently, it cannot serve directly as an efficient laser or LED light source device and struggles to make significant contributions in the optoelectronics field.

To achieve optical communication on chips (faster and more energy saving than electronic transmission), engineers typically need to heterogeneously integrate expensive III-V materials (such as gallium arsenide), a process that is complex and costly. Therefore, scientists have long been dedicated to developing alternatives using Group IV materials, among which germanium-tin alloys (GeSn) are regarded as the "holy grail" of the semiconductor field.

Unlike III-V materials, germanium and tin both belong to Group IV elements. Doping germanium lattices with a specific proportion of tin can alter the band structure, transforming it into a "direct bandgap" material, thereby achieving higher carrier mobility; meanwhile, Group IV elements are highly compatible with existing silicon integrated circuit processes, making them a focal point in optoelectronic applications.

Historically, the main challenge with germanium-tin alloys was that these two elements are difficult to react chemically under conventional conditions. Only recently, a team from the University of Edinburgh successfully prepared a stable germanium-tin alloy by heating a germanium-tin mixture to 1200°C and applying pressures up to 10 GPa, enabling it to remain stable at room temperature and atmospheric pressure.

Whether for next-generation electronic devices or data centers with continuously growing power demands, the future relies on optical transmission to improve energy efficiency; new materials are expected to enable faster device operation and lower energy consumption.

Related papers were published in the Journal of the American Chemical Society (American Chemical Society, ACS).

Source: TechNews