Transparent, Flexible Silicon Nanostructured Wire Networks with Seamless Junctions for High-Performance Photodetector Applications

Abstract

Optically transparent photodetectors are crucial in next-generation optoelectronic applications including smart windows and transparent image sensors. Designing photodetectors with high transparency, photoresponsivity, and robust mechanical flexibility remains a significant challenge, as is managing the inevitable trade-off between high transparency and strong photoresponse. Here we report a scalable method to produce flexible crystalline Si nanostructured wire (NW) networks fabricated from silicon-on-insulator (SOI) with seamless junctions and highly responsive porous Si segments that combine to deliver exceptional performance. These networks show high transparency (∼92% at 550 nm), broadband photodetection (350 to 950 nm) with excellent responsivity (25 A/W), optical response time (0.58 ms), and mechanical flexibility (1000 cycles). Temperature-dependent photocurrent measurements indicate the presence of localized electronic states in the porous Si segments, which play a crucial role in light harvesting and photocarrier generation. The scalable low-cost approach based on SOI has the potential to deliver new classes of flexible optoelectronic devices, including next-generation photodetectors and solar cells.

Si/CuIn0.7Ga0.3Se2 Core–Shell Heterojunction for Sensitive and Self‐Driven UV–vis–NIR Broadband Photodetector

“…Meanwhile, this photodetector exhibits excellent characteristics in terms of broad photoresponse range from 300 to 1100 nm, large responsivity of 0.33 A W −1 , ultrahigh detectivity of 1.6 × 10 13 Jones, fast response speed of 823/356 µs, and robust stability. The performance characteristics are comparable to or surpass those reported for Si or CIGS‐based photodetectors in previous work, as shown in Table 1 …”

Low‐dimensional nanomaterial/Si heterostructure‐based photodetectors

“…As shown in Figure B, Rao and coworkers achieved both flexibility and transparency by combining Si nanostructured wire networks and PET substrates. The porous nanostructure provided up to 92% transparency in the designed photodetector . The broad detection range (350~950 nm) of Si remained.…”

“…Copyright 2018, American Chemical Society. B, Schematic illustration of Si nanowire network Copyright 2018, American Chemical Society. C, Schematic band structure of the annealed ITO/Si heterojunction under uniaxial tensile strain or not .…”

“…The porous nanostructure provided up to 92% transparency in the designed photodetector. 120 The broad detection range (350~950 nm) of F I G U R E 1 1 Schematic band diagrams of a p-Si/n-CdS p-n junction without (black dotted line) and with (dark yellow line) a compressive strain under A 0 V forward bias and under B 1.5 V forward bias. Schematic band diagrams of an n-Si/n-CdS n-n junction without (black dotted line) and with (dark yellow line) a compressive strain under C 0 V forward bias and D under 1.5 V forward bias.…”

Semitransparent, Flexible, and Self‐Powered Photodetectors Based on Ferroelectricity‐Assisted Perovskite Nanowire Arrays

“…Emerging as important components in next‐generation optoelectronic devices, transparent and flexible photodetectors can be integrated into portable and wearable devices as optical sensors while allowing light to pass through and maintaining transparency . Recently, hybrid organic–inorganic CH 3 NH 3 PbX 3 (X = Cl, Br, I) perovskites attract immense research interests due to their high carrier mobility, low excitation binding energies, long carrier diffusion length, good solution processability, and low temperature crystallinity .…”