Intense terahertz (THz) pulses have been shown to induce photoluminescence (PL) quenching in bulk semiconductors. We show that in addition to PL quenching near the bandgap, intense THz pulses enhance the high-energy tail of the PL in GaAs. Furthermore, we propose a simple model that accounts for both PL quenching and enhancement where THz-induced hot carriers directly enhance high-energy PL but reduce overall radiative efficiency due to ultrafast diffusion. Exploring the interplay between THz-induced PL enhancement and quenching over a range of excitation parameters reveals a reduction of integrated PL at low photoexcitation fluence, while at higher fluences, the amplitude of the PL quenching is balanced by that of the PL enhancement.

中文翻译：

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用强太赫兹脉冲增强热载流子光致发光

强烈的太赫兹 (THz) 脉冲已被证明会在体半导体中引起光致发光 (PL) 猝灭。我们表明，除了带隙附近的 PL 淬灭之外，强烈的太赫兹脉冲增强了 GaAs 中 PL 的高能尾。此外，我们提出了一个简单的模型来解释 PL 淬灭和增强，其中 THz 诱导的热载流子直接增强高能 PL，但由于超快扩散而降低了整体辐射效率。探索 THz 诱导的 PL 增强和在一系列激发参数下淬灭之间的相互作用，揭示了在低光激发能量密度下积分 PL 的减少，而在较高能量密度下，PL 淬灭的幅度与 PL 增强的幅度相平衡。