Proc. SPIE. 10206, Disruptive Technologies in Sensors and Sensor Systems
KEYWORDS: Semiconductors, Data modeling, Polarization, Interference (communication), Gallium nitride, Monte Carlo methods, Carrier dynamics, Statistical modeling, Process modeling, General packet radio service
Monte Carlo (MC) methods have been shown to capture the ultrafast dynamics of carriers and resulting luminescence in photo-excited GaN. These calculations have assumed a homogeneous material under uniform illumination. We investigate the development of surrogate models to represent the carrier dynamics with fewer degrees of freedom, with the ultimate goal of computing the response of structured materials under inhomogeneous illumination profiles. These models are presently based on the extraction of mean and variance information from single data sets, through the use of fits to s piece-wise linear basis. Two models are then developed, one based on the mean and variance directly, and one on a Gaussian process regression model. New carrier populations with similar statistical profiles are then generated from these models to determine the amount of data reduction that can be obtained.
We present a comparison among GaN/AlGaN, GaN/InAlGaN, and GaAs/AlGaAs quantum cascade structures based on a Monte Carlo study of carrier dynamics, to highlight the improvements offered by nitride latticematched structures. We take into account the interactions of electrons with other electrons as well as LO-phonons. The results obtained from the Monte Carlo simulations are used to calculate the population inversion of each structure to determine its temperature dependence. This study shows that the nitride-based structures offer significantly improved high-temperature performance compared to the GaAs device, including the possibility of room-temperature operation. Furthermore, by virtue of its lattice-matched nature, the GaN/InAlGaN materials system can potentially enable the high-quality growth of thick quantum cascade structures without plastic relaxation, as a way to overcome the structural issues that have so far hindered the development of these devices with nitride semiconductors.
The growing importance of In<sub>0:18</sub>Al<sub>0:82</sub>N stems from the fact that it can be grown lattice matched to GaN and for its potential applications in a large number of electronics and optoelectronics devices. In this work we employed
a full band Monte-Carlo approach to study the carrier transport properties of this alloy. We have computed the temperature and doping dependent electron and hole mobilities and drift velocities. Furthermore, for both sets of transport coefficients we have developed a number of analytical expressions that can be easily incorporated in drift-diffusion type simulation codes.