Large-gain low-voltage and wideband organic photodetectorsviaunbalanced charge transport

Abstract

Tetracyanoquinodimethane leads to trap-enhanced photoconductive gain and highly efficient broadband sensing for bulk heterojunction organic photodetectors.

Photomultiplication‐Type Organic Photodetectors for Near‐Infrared Sensing with High and Bias‐Independent Specific Detectivity

“…For our PM‐type device, in the most advantageous operation region, where the effect of the dark current does not overwhelm the enhancement in R , an impressive D * above 10 13 Jones can be realized, superior to D * provided by the pin/nip PV‐OPDs and comparable to results for the best reported PM‐OPDs in the literature. [ 19 , 40 , 41 , 42 ] In contrast to the two PV‐OPDs whose D * decreases with increased reverse bias, the outstanding D * of the PM‐OPD can be maintained up to −10 V. The ideal balance between dark current and R in PM‐type devices is rarely reported. Besides that, the employed vacuum deposition of the PM‐OPDs offers the possibility of straight upscaling of the manufacturing and commercialization since thermal evaporation is the most established production technique for organic optoelectronic devices (e.g., organic light‐emitting diodes and organic solar cells).…”

Narrowband organic photodetectors – towards miniaturized, spectroscopic sensing

“…47 Since then, PM-OPDs with photocurrent gain, achieved by trap-state-induced tunneling injection of charge carriers, were broadly investigated. 25,[48][49][50] Similar to the previously described organic phototransistors, PM type OPDs can pave the way for improving the performance of traditional PDs under low light intensity or in low absorption wavelength regions (e.g. NIR).…”

“…The buildup of charge carriers introduces a localized electric field which induces an interfacial energy level bending to assist tunneling injection of the opposite charge carrier type from the external circuit at reverse bias, resulting in PM photogain enhancement with an internal quantum efficiency (IQE) higher than 100%. 48,50,65 Meanwhile, low dark currents can be maintained due to the rectifying characteristics of these OPDs.…”

“…[28][29][30] Such materials can also be sucessfully utilized for achieving broadband OPDs. Compared to their broadband counterparts, narrowband OPDs are endowed with higher performance for the mentioned applications like high-resolution imaging, 72 medical diagnosing under low light intensity, 50 material sensing, and light communication for specific target wavelength windows. 73 Moreover, narrowband OPDs with tunable wavelength feature can be employed to realize spectrometers with simple architecture, at low-cost and composed of non-heavy metals and harmless materials.…”

Carrier Blocking Layer Materials and Application in Organic Photodetectors

“…This work brings new elements in the understanding of the impact of oxygen contamination in the performance degradation of organic solar cells or photodiodes. In conventional OPDs, using PEDOT:PSS as the anodic interface to modify ITO could reduce the oxidation potential, enhance conductivity, and is beneficial to the transport of holes and energy level matching [125][126][127]. Zhang's group [128] reported the ternary OPDs used one interface layer of PEDOT:PSS, which have similar EQE values of ≈2000% and specific D* larger than 10 11 Jones at −50 V bias under the bottom and top illumination conditions.…”