کنفرانس مهندسی برق ایران

صفحه اصلی / سی و سومین کنفرانس بین المللی مهندسی برق

Investigation of Impact Ionization Variations Versus Electric Field and Temperature in Compound Semiconductors for UV-APD Applications

نویسندگان :

Mohammad hossein Khoddami¹ Hassan Kaatuzian² Mohammad hossein Asgari³

1- دانشگاه صنعتی امیرکبیر(پلی تکنیک تهران) 2- دانشگاه صنعتی امیرکبیر(پلی تکنیک تهران) 3- دانشگاه صنعتی امیرکبیر(پلی تکنیک تهران)

کلمات کلیدی :

Impact Ionization Coefficients،Okuto-Crowell model،UltraViolet،GaN،Temperature Dependence

چکیده :

This paper investigates the impact ionization coefficients for two types of carriers, electrons and holes, using the Okuto-Crowell model and related equations. We examine how these coefficients depend on electric field and temperature in various sample materials, specifically GaN, AlGaN, 4H-SiC, and Ga2O3, which are suitable for ultraviolet Avalanche Photodiode (APD) applications. This makes them highly suitable for creating ultraviolet photodetectors since they have a high band gap that puts them in the ultraviolet light absorption range. As a result, expensive gratings and filters customarily necessary for high-sensitivity detectors to ultraviolet radiation are not required. A typical architecture for ultraviolet detectors is the Separate Absorption and Multiplication (SAM) structure, which consists of two regions: the absorption region (A) and the multiplication region (M). Therefore, investigating the materials used in these regions is crucial from various perspectives. Selecting materials with high ionization coefficients at elevated temperatures and electric fields in the multiplication region is important. In our studies, we found that, based on the coefficients from the Okuto-Crowell model, GaN exhibits exceptionally high ionization coefficients, approximately αe =8.5 × 106 and αh=7.5 × 106 at an electric field of 5 MV/m and temperature of 400 K. Additionally, at very low temperatures, around 250 K, materials such as 4H-SiC and AlGaN can exhibit impact or avalanche ionization properties due to their crystal lattice structure. In contrast, GaN and Ga2O3 do not demonstrate avalanche conditions at this temperature. Finally, our analysis's results are almost consistent with some of the experimental results presented in [20]. However, a slight difference is related to the determination of the input parameters of the Okuto-Crowell equation.