Binary Multifunctional Ultrabroadband Self‐Powered g‐C3N4/Si Heterojunction High‐Performance Photodetector. Issue 14 (18th May 2018)

• Record Type: Journal Article
• Authors: Prakash, Nisha; Kumar, Gaurav; Singh, Manjri; Barvat, Arun; Pal, Prabir; Singh, Surinder P.; Singh, H. K.; Khanna, Suraj P.
• Is Part Of: Advanced optical materials. Volume 6:Issue 14(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-05-18
• Subjects: binary switching -- energy harvesting -- g‐C3N4 -- hybrid photodetectors -- photosensitivity; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.201800191
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Compact optical detectors with fast binary photoswitching over a broad range of wavelength are essential as an interconnect for any light‐based parallel, real‐time computing. Despite of the tremendous technological advancements yet there is no such single device available that meets the specifications. Here a multifunctional self‐powered high‐speed ultrabroadband (250–1650 nm) photodetector is reported based on graphitic carbon‐nitride (g‐C3 N4 )/Si hybrid 2D/3D structure. The device shows a novel binary photoswitching (change in current from positive to negative) in response to OFF/ON light illumination at small forward bias (≤0.1 V) covering 250–1350 nm. At zero bias, the device displays an extremely high ON/OFF ratio of ≈1.2 × 10 5 under 680 nm (49 µW cm −2 ) illumination. The device also shows an ultrasensitive behavior over the entire operating range at low light illuminations, with highest responsivity (1.2 A W −1 ), detectivity (2.8 × 10 14 Jones), and external quantum efficiency (213%) at 680 nm. The response and recovery speeds are typically 0.23 and 0.60 ms, respectively, under 288 Hz light switching frequency. Dramatically improved performance of the device is attributed to the heterojunctions formed by the ultrathin g‐C3 N4 nanosheets embedded in the Si surface. Abstract : First realization of novel binary photoswitching over an ultrabroadband range is demonstrated. The device employs a hybrid 2D/3D structure based on silicon platform which opens up a possibility for the application of graphitic carbon‐nitride (g‐C3 N4 ) nanosheets for light‐based binary communications, interconnects for optical computing and weak signal detections. An overlayer of g‐C3 N4 may also significantly improve the performance of silicon solar cells.