Figure 3

(a,b) Current density‒voltage (J‒V) characteristics of solCIGS and K-solCIGS photodiodes in the dark and under illumination at the NIR wavelength of 980 nm (PIN = 31.4 mW cm−2). Note that the graphs in (a) and (b) show a linear plot and a semi-logarithmic plot of the J‒V characteristics, respectively. (c) Time-dependent photoresponse of solCIGS and K-solCIGS devices at − 0.4 V (λ = 980 nm, PIN = 0.03 mW cm−2). (d) − 3 dB bandwidth comparison of solCIGS and K-solCIGS devices as a function of incident pulse laser frequency under NIR light of 980 nm.