電漿子強化n型矽半導體之歐傑復合效應

Abstract

在過去五十年之中，關於多體效應所引起的電漿子對歐傑復合的影響之相關研究並不多。近期有學者透過第一原理來計算n型矽半導體的歐傑生命週期，其計算結果仍然較實驗數據大，並且在此計算中未將電漿子的影響納入考慮。在這篇論文之中，我們應用微觀的歐傑復合公式來重現第一原理的計算結果。由於電漿引致電位擾動遠比歐傑復合效應慢，因此在歐傑復合效應中，電漿子的效應必須在在長波長近似下考慮，其會造成間接的效應：電性能隙窄化以及熱電子。我們發現電性能隙窄化對於歐傑生命週期的影響不明顯。在另一方面，加入熱電子效應的模擬結果與實驗相吻合，因此熱電子效應為電漿子影響歐傑復合效應的主要機制。

The effects of many-body plasmons on the Auger recombination in doped semiconductors were less studied over the past five decades. Recent first-principles calculations on n-type silicon, without participation of plasmons, yielded Auger lifetimes that are higher than experimental values. In this thesis, we make use of an existing microscopic Auger recombination formalism with which to reproduce first-principles results. Plasmons-enhanced potential fluctuations are not faster than the Auger event; therefore, the effect of plasmons can have only the indirect effect in the long wavelength limit: the experimental electrical bandgap narrowing and the experimental electron temperature. The electrical bandgap narrowing is found to be weak in determining the Auger lifetime. On the contrary, the plasmons-induced conduction electron heating is determined to be the dominant mechanism. The calculated results with electron heating included are consistent with the experimental observations.