Effect of rapid thermal annealing on the electrical properties of dilute GaAsPN based diodes

Abstract

The effect of rapid thermal annealing on the electrical properties of p ++ GaP/p -GaAsPN/n + GaP diodes were investigated by using Current -Voltage (I-V), Capacitance-Voltage (C-V) and Deep Level Transient Spectroscopy (DLTS) techniques in the temperature range from 100K to 440K. It was observed that rapid thermal annealing treatment improves the electrical characteristics of as-grown structures. The annealed samples showed an ideality factor lower than the as-grown samples for all temperatures. The ideality factor values from I-V characteristics has changed between 6.8 and 1.9 in the temperature range of 110-430K for as grown diode, and between 6.3 and 1.44 in the temperature range 100-400K for the annealed diode. On the other hand, the barrier height increases and the ideality factor decreases with increasing temperature for all samples. The barrier height values has changed between 0.29 eV and 0.71eV in the temperature range of 190-430K for as grown diode, and between 0.38 eV and 0.77eV in the temperature range 180-420K for the annealed diode. High values of barrier heights were observed in the annealed samples due to the barrier height in-homogeneities at the p-i-n junction.The net acceptor concentration was calculated to be 1.18 x10 18 cm -3 and 2.11x10 18 cm -3 for the as-grown and annealed GaAsPN layers, respectively. The net acceptor concentration increases by ~56% and the leakage current of the GaAsPN/GaP p-i-n junction decreases by1-2 orders after RTA. DLTS and Laplace-DLTS measurements reveal three hole traps, H1an(0.06eV), H2an(0.065eV) and H3(0.23eV) in the annealed samples as compared with two hole traps, H4ag(0.07eV) and H5(0.25eV) in the as-grown samples. After rapid thermal annealing an extra shallow trap is created.

Analysis of Current Transport Mechanism in AP-MOVPE Grown GaAsN p-i-n Solar Cell

“…The temperature evolution of n is shown in Figure 8b. In the HT region, n varies in the range from 1.29 to 1.55, while in the LT region, ideality factor linearly increases as the temperature lowers, reaching 3.01 at 100 K. The increase in ideality factor with the decrease in temperature is a well-known phenomenon related to thermionic emission [77,78]. Han et al investigated MBE-grown single-junction GaAs solar cell by means of J-V measurements in the 100-400 K temperature range.…”

“…Alburaih investigated the influence of post-growth annealing on the properties of MBE-grown dilute nitride GaAsNP diodes. He noticed that ideality n decreases from 6.8 at 110 K to 1.99 at 300 K for the as-grown diode, while, for the annealed one, the n drops from 6.3 at 100 K to 2.7 at 300 K [78]. In CdTe-based solar cells, Fiat et al obtained an n of 5.43 at 80 K; then, n decreased to 1.4 at 300 K [80].…”