A facile covalent strategy for ultrafast negative photoconductance hybrid graphene/porphyrin-based photodetector

Abstract

As a powerful complement to positive photoconductance (PPC), negative photoconductance (NPC) holds great potential for photodetector. However, the slow response of NPC relative to PPC devices limits their integration. Here, we propose a facile covalent strategy for an ultrafast NPC hybrid 2D photodetector. Our transistor-based graphene/porphyrin model device with a rise time of 0.2 ms and decay time of 0.3 ms has the fastest response time in the so far reported NPC hybrid photodetectors, which is attributed to efficient photogenerated charge transport and transfer. Both the photosensitive porphyrin with an electron-rich and large rigid structure and the built-in graphene frame with high carrier mobility are prone to the photogenerated charge transport. Especially, the intramolecular donor-acceptor system formed by graphene and porphyrin through covalent bonding promotes photoinduced charge transfer. This covalent strategy can be applied to other nanosystems for high-performance NPC hybrid photodetector.

Homo‐type α‐In2Se3/PdSe2 Ferroelectric van der Waals Heterojunction Photodetectors with High‐performance and Broadband

“…[6][7][8][9][10] The composition of the target device material determines the working mechanism and performance of the photodetector. Currently, twodimensional (2D) semiconductor materials, such as graphene, [11,12] transition metal dichalcogenides (TMDs), [13][14][15][16][17] black phosphorus (BP), [18][19][20] III-VI compounds, [21][22][23] and other layered semiconductors, [24,25] have attracted wide attention in optoelectronic detection applications due to their excellent physical properties, such as high carrier mobility, strong light-matter interactions, and broadband light absorption. However, most photodetectors based on a single 2D material have some limitations when it comes to simultaneously achieving high-performance and broadband detection.…”

Large-area, size-controlled and transferable graphene oxide-metal films for humidity sensor

“…Graphene demonstrates unique physical and chemical properties, so it has attracted great attention since it was separated from graphite by mechanical exfoliation [1]. Up to now, graphene and its derivatives have been employed in various electronic devices, such as sensors, solar cells, photodetectors, supercapacitors and actuators [2][3][4][5][6][7][8][9]. However, although graphene and its derivatives show extraordinary talent in research field, they are still not widely used in actual production.…”

Observation of Negative Photoconductivity in (CH3NH3)3Bi2(BrxCl1–x)9: Correlating Ion Migration, Stability, and Efficiency in Mixed Halide Perovskite Solar Cell

“…Further, observed negative photocurrent may be direct evidence of the largely discussed (and debated too) phenomenon of ion migration on the stability of the PSC in the recent past. The NPC effect is faster than conventional optoelectronic charge transport, so it helps to develop low-power, high-speed photodetectors. , For solar cells, of course, NPC results in lower solar cell efficiency; for example, Bi-based perovskite tends to show poor efficiency despite being an excellent lead-free perovskite alternative. , …”

“…The NPC effect is faster than conventional optoelectronic charge transport, so it helps to develop low-power, high-speed photodetectors. 68,69 For solar cells, of course, NPC results in lower solar cell efficiency; for example, Bi-based perovskite tends to show poor efficiency despite being an excellent leadfree perovskite alternative. 37,38 ■ METHODS Chemicals.…”