Forward Current Conduction Mechanism of Mechanically Exfoliated β-Ga2O3/GaN pn Heterojunction Diode

In this letter, we fabricated the mechanically exfoliated β-Ga2O3/GaN pn heterojunction diode and carried out the electrical characteristics measurements. At room temperature, the diode shows a good rectifying property, with a turn-on voltage of 3.9 V-4.6 V and rectifying ratio greater than 106 @ 20 V. From the 1/C2 vs V plot, the built-in voltage is determined to be 3.4 V and the energy band diagram of the heterojunction is also constructed. According to the temperature dependent I-V cures, three different forward current conduction mechanism can be identified, recombination-tunneling mechanism, trap charge limited space-charge-limited-current(SCLC) and SCLC mechanism for I < 10−7 A (region I), 10−7 < I < 10−4 A (region II) and I > 10−4 A (region III), respectively. While in region II, two different Et from exponential trap distribution model is determined to be 0.514 eV, 0.310 eV and the corresponding trap density is 1.63 × 1016 cm−3 and 1.71 × 1016 cm−3, respectively.