Figure 5
(a,c) Simulated spatial distribution of photo-carrier-induced electron concentration and hole concentration for n-type Si nanowires under strong excitation. The excitation is centered at 4 μm. Decay lengths are 959/836 nm for (a) and 1100/963 nm for (c) in the cathode/anode regions, respectively. (b,d) Scanning photocurrent profiles. The corresponding photocurrent decay lengths are 1.77/2.42 μm for (b) and 1.69/2.27 μm for (d) on the cathode/anode sides, respectively. The mobility model proposed by Klaassen is used in (a,b), and Dorkel-Leturcq model is adopted in (c,d). The applied electric field of the device is 500 V/cm and the pumping density is 7 × 105 W/cm2. The fitting curves using simple exponential decay functions are shown as dashed blue lines and corresponding fitted lengths on both sides are also shown in the figures.
