New Device Physics of Cross-Gap Electroluminescence in Unipolar-Doped InGaAs/AlAs RTDs
2019 3rd Quarter (CY)
10199510
10.1109/DRC46940.2019.9046392
2019 Device Research Conference (DRC)
P. FakhimiW-D. ZhangT. A. GrowdenE.R. BrownR. DroopadK.M. HansenP. R. Berger
3V into the second positive differential resistance (PDR) region supports our thesis that the holes for the light emission are produced by interband tunneling, not impact ionization [4]. Fig. 5 shows an overlay plot of the normalized EL spectra of an RTD biased at 3.5 V with peaks marked and the theoretically modeled bandgap of In0.53Ga0.47As at various temperatures. The consistency between the theoretical model and measured bandgap corresponding to the spectra peak further supports the theory that describes the light emission as being cross-gap, radiative recombination in the InGaAs emitter [Fig. 5, Fig. 1]. The decreasing trend in full width at half maxima (FWHM) with a decrease in temperature could be due to a reduction in phonon scattering [Fig. 6] [5]. The preliminary external quantum efficiency (EQE) measurements resulted in an EQE of ~0.44% for unipolar-doped In0.53Ga0.47As/AlAs DBRTDs. Balancing the electron resonant and interband tunneling currents via tunneling engineering can result in substantially improved EQEs.]]>