Lithography-Free, Low-Cost Method for Improving Photodiode Performance by Etching Silicon Nanocones as Antireflection Layer

Figure 2

(a) Comparison of 3-inch blackened silicon (left) and polished silicon wafer (right). (b) Treated (left) and untreated (right) photodiode taped on a piece of glass slide. (c) Cross-sectional SEM image of blackened photodiode. (d) Effective refractive index of nanocone forest and the light path from air to silicon with nanocone structure, the reflection of light is minimal at each depth of the sample. (e) Schematic to show the effective refractive index of nanocone array on black silicon.

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