Hot luminescence spectroscopy of non-radiative recombination in silicon
Final Report Abstract
Silicon's role in transistors, microchips, and solar cells has driven a technological revolution. Understanding its electrical properties, crucial for performance in electronic components, particularly in solar cells, remains complex due to various recombination mechanisms. The project aimed to revolutionize the understanding of silicon's recombination mechanisms through hot luminescence spectroscopy. Leveraging advancements in laser and detector technology, it aimed to directly analyse Auger and defect-Auger recombination, promising insights into fundamental physics and technological advancements. The experimental design, tailored to the requirements of measuring hot luminescence in silicon, underwent iterative improvements: it allows for the detection of just a few photons per hour, being limited only by intrinsic limitations. By shortening measurement times from weeks to minutes, hot luminescence could be detected efficiently. Yet, an unexpected discovery altered the course of investigation. The deposition of aluminium oxide on the silicon surface on all specimens to suppress surface recombination was discovered to lead to the formation of a two-dimensional electron-hole layer, a phenomenon unprecedented in such a silicon heterostructure. The project was marked by the diligent pursuit of uncovering the cause behind the unexpected emission, a task that engaged the recipient of grant throughout the entirety of the project timeline. While intriguing, this unexpected effect generated intense hot luminescence, hindering the planned investigation. Despite this deviation of plan, the project's significance remains undiminished. By confronting this unexpected challenge, the research opens new avenues for exploration, offering insights into previously unexplored territories of silicon charge carrier behaviour.
Publications
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Hot luminescence of two-dimensional electron hole systems in modulation-doped silicon. Journal of Applied Physics, 135(7).
Heinz, Friedemann D.; Kwapil, Wolfram & Glunz, Stefan W.
