Fig. 1. Schematic of different treatment processes of samples

Fig. 2. (a) PL spectra at room temperature of samples for different passivation time; (b) AFM diagram of GaAs samples without passivation; (c) AFM diagram of GaAs samples after passivation treatment for 25 min

Fig. 3. PL spectra of samples after passivation treatment for different standing time

Fig. 4. Photocurrent and dark current curves of three groups of samples

Fig. 5. Responsivity at 300-900 nm of samples. (a) Different samples; (b) sample 3 after 30 d

Fig. 6. Schematic of energy bands of GaAs samples. (a) Dark; (b) sample 1, under light; (c) sample 2, under light; (d) sample 3, under light