New Device Physics of Cross-Gap Electroluminescence in Unipolar-Doped InGaAs/AlAs RTDs

Abstract

Double barrier resonant tunneling diodes (DBRTDs) exhibit a characteristic negative differential resistance (NDR), which allows for high-speed oscillation and switching; e.g. In 0.53 Ga 0.47 As/AlAs DBRTDs for high-speed oscillation applications [1], [2]. Recently, a cross-gap electroluminescence (EL) phenomenon from InGaAs DBRTDs at room temperature was discovered despite the absence of p-doped layers [3]. This unipolar-doped EL had not been previously reported in the past 40+ years of RTD history. The indispensable holes for the light emission are thought to be produced by interband tunneling through the narrow bandgap of In 0.53 Ga 0.47 As, which is illustrated in Fig. 1. The radiative recombination is thought to occur primarily in the In 0.53 Ga 0.47 As emitter region, and thus the emission spectrum is near the bandgap of In 0.53 Ga 0.47 As (∼1650 nm at 295 K). The EL property combined with high-speed modulation can be utilized for future high-speed optical clocking applications. In this abstract we report a more detailed characterization of unipolar-doped In 0.53 Ga 0.47 As/AlAs DBRTDs to gain a better understanding of the new EL phenomenon.