Graphene-pyramid textured silicon heterojunction for sensitive near-infrared light photodiode

CVD Graphene on Textured Silicon: An Emerging Technologically Versatile Heterostructure for Energy and Detection Applications

“…[ 68,69 ] However, Wang et al. [ 74 ] used a solution of KOH/IPA for anisotropic etching of n ‐type Si substrates to prepare MP textured‐Si substrates. The cleaned n ‐type Si substrates were immersed into a solution of KOH (2–4 wt%)/IPA (5 vol%) at 85 °C for 30 min.…”

“…[ 52,103 ] The SiNWs were prepared by the MACE method as already discussed in detail earlier, whereas the MP textured‐Si as shown in Figure a was obtained by using a well‐established anisotropic alkali etching method. [ 74 ] The width and height of MP were found to be in the range of 1 to 5 and 1 to 2 µm, respectively. The reflectance spectra of the planar‐Si and MP textured‐Si at 550 nm is shown in Figure 10b, where the reflectance decreased significantly from 38 (planar Si) to 13% for the MP textured‐Si, that confirmed the greater light absorption ability of the MP textured‐Si.…”

“…Therefore, a remarkable advancement in this area has also taken place recently. [ 43,69,70,72,74,75,83 ] The performance of PDs including graphene/Si Schottky junction‐based PDs are mainly evaluated by responsivity, specific detectivity, noise equivalent power (NEP), normalized photo‐to‐dark current ratio, etc. Responsivity ( R ) is given by the following relation: where, I ph is the measured photo current, P in is the incident optical power density and A is the active area.…”

“…Similarly, Wang et al. [ 74 ] (in 2017) fabricated a NIR light photodiode by transferring p ‐type CVD MLG onto n ‐type MP textured‐Si. The fabricated Schottky junction‐based photodiode also behaved as a NIR light photodetector with a high on/off ratio.…”

“…[58,73] Similarly, MP textured-Si substrates as shown in Figures 3a and 4a have also been employed successfully to fabricate CVDgraphene/MP-textured Si heterostructures for Schottky junction PDs, either by the direct CVD growth of graphene or by transferring CVD grown graphene on MP-textured Si substrates. [69,74] As discussed earlier, the MP textured-Si substrates can be fabricated via simple anisotropic etching processes by using solutions of KOH (3 wt%)/NaSiO 3 (1 wt%)/isopropyl alcohol (8 vol%) and DI/TMAH/IPA (12:1:1), respectively. [68,69] However, Wang et al [74] used a solution of KOH/IPA for anisotropic etching of n-type Si substrates to prepare MP textured-Si substrates.…”