[23p-D316-1~17] 13.6 ナノ構造・量子現象・ナノ量子デバイス

▲ [23p-D316-4] Electron temperature in semiconductor double barrier thermionic cooling heterostructures

〇Xiangyu Zhu¹、Marc Bescond²、Gerald Bastard³、Naomi Nagai¹、Kazuhiko Hirakawa^1,2 (1.IIS/INQIE,Univ. of Tokyo、2.LIMMS-CNRS、3.Ecole Normale Superieure)

キーワード：semiconductor, heterostructure, thermionic cooling

Managing rapid increase in thermal power densities associated with device miniaturization is a major technological challenge. Development of new efficient cooling technologies is therefore urgently required for future progress in electronics. Solid-state cooling devices can be one answer, owing to their high efficiency and compatibility for integration. To achieve efficient cooling, we have been working on semiconductor double barrier heterostructures to utilize the thermionic cooling effect. In the present heterostructure, cold electrons are first injected into the quantum well (QW) by resonant tunneling through the thin barrier (emitter barrier). Subsequently, hot electrons are removed by thermionic emission over the second thick barrier (collector barrier). This sequential two-step conduction process is essential for the cooling effect. To quantitatively understand the conduction process, we have developed an analytical theory to calculate the two-step current and compared it with experiment. In this work, we have considered not only the current flow but also the energy balance in the electron system in the QW. The electron temperature in the QW can be calculated and compared with experimental data.
To clarify the electron cooling behavior, we have measured voltage-dependent photoluminescence (PL) spectra. The high-energy tail of the PL spectra reflects the electron distribution function, from which we can determine Te. The calculated result gives reasonable accounts for the experiment. We will discuss more detail at the conference.