Deep Ultraviolet Photodetector with Ultrahigh Responsivity based on a Nitrogen‐Doped Graphene‐Modified Polypyrrole/SnO₂ Organic/Inorganic p–n Heterojunction

Abstract

Deep ultraviolet monitoring is realized via a high crystal quality SnO2 microwire (MW)‐based photodetector (PD). This is then combined with 2D nitrogen‐doped graphene (NGr), conducting polymer polypyrrole (PPy), and an in situ polymerization‐fabricated composite film PPy‐NGr to construct an organic–inorganic p–n heterojunction PD. The long response time brought on by the oxygen adsorption of SnO2 MW is greatly decreased via coating with the aforementioned materials. A defect response is created by the surface dangling bonds of SnO2 MW, which can be effectively suppressed by the PPy. Absorption in the deep ultraviolet region (<240 nm) by PPy results in a blue shift of the response peak of the PPy/SnO2 heterojunction PD compared to that of a single SnO2 PD. The introduction of NGr improves the detection performance by providing a smoother energy band migration to reduce photogenerated carrier recombination and stacking at the potential barrier. The ultrahigh responsivity of PPy‐NGr/SnO2 PD is 4594.25 A W−1 and the detectivity is 6.47 × 1011 Jones, 40 and nine times greater, respectively, than those of a PPy/SnO2 PD under a 5 V reverse bias and 240‐nm light irradiation (18.75 µW cm−2). The novel strategy provides a reference for the future design of high‐performance heterojunction PDs.

Recent advances in enhancing the photodetector performance of 2D materials by combining them with organic thin films

“…The PPy-NGr/SnO 2 heterojunction photodetector exhibits an exceptionally high responsivity (4594.25 A W −1 ) and a high detectivity (6.47 × 10 11 Jones). 139 These characteristics result from the substantial built-in electric field (NGr/SnO 2 , PPy/SnO 2 , and PPy-NGr/SnO 2 ), accelerating the efficient dissociation of photogenerated excitons. At the same time, NGr mitigates the valence band offset between PPy and SnO 2 .…”

An ultraviolet, self-powered, and large area photodetector based on a n-SnO2/p-spiro-OMeTAD organic–inorganic heterojunction

“…8,9 Photodetectors based on SnO 2 inorganic heterojunctions (IHs) have been widely studied. [10][11][12] A self-powered photodetector on the basis of a n-SnO 2 microwire/p-InGaN IH was constructed, and it responded to ultraviolet-visible (330-530 nm) light irradiation. 13 In addition, a photodetector based on SnO 2 /NiO IH was fabricated by depositing NiO using magnetron sputtering and SnO 2 using the electron beam evaporation technique.…”

Self-powered stable high-performance UV–Vis–NIR broadband photodetector based on PVP-Cobalt@Carbon nanofibers/n-GaAs heterojunction

“…In the simplest approach, a heterojunction with one wide bandgap and the other narrow bandgap direct bandgaps can provide a photodetector operating in a wide spectral region with proper optimization. For this purpose, a large number of organic, inorganic-based or hybrid heterojunctions have been widely studied for this purpose in recent years [18][19][20][21][22][23][24][25][26].…”