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

Abstract

Highly responsive organic photodetectors allow a plethora of applications in fields like imaging, health, security monitoring, etc. Photomultiplication‐type organic photodetectors (PM‐OPDs) are a desirable option due to their internal amplification mechanism. However, for such devices, significant gain and low dark currents are often mutually excluded since large operation voltages often induce high shot noise. Here, a fully vacuum‐processed PM‐OPD is demonstrated using trap‐assisted electron injection in BDP‐OMe:C60 material system. By applying only −1 V, compared with the self‐powered working condition, the responsivity is increased by one order of magnitude, resulting in an outstanding specific detectivity of ≈1013 Jones. Remarkably, the superior detectivity in the near‐infrared region is stable and almost voltage‐independent up to −10 V. Compared with two photovoltaic‐type photodetectors, these PM‐OPDs exhibit the great potential to be easily integrated with state‐of‐the‐art readout electronics in terms of their high responsivity, fast response speed, and bias‐independent specific detectivity. The employed vacuum fabrication process and the easy‐to‐adapt PM‐OPD concept enable seamless upscaling of production, paving the way to a commercially relevant photodetector technology.

Ultraviolet Narrowband Photomultiplication Type Organic Photodetectors with Fabry−Pérot Resonator Architecture

“…[ 1–5 ] OPDs can be classified as photodiode type OPDs (PD‐OPDs) with external quantum efficiency (EQE) <100% and photomultiplication type OPDs (PM‐OPDs) with EQE >100% according to their working mechanism. [ 6,7 ] In light of the bandwidth of photoresponse, the OPDs can be divided into broadband and narrowband OPDs. [ 8,9 ] Broadband PD‐OPDs can be easily realized by employing active layers with wide photon‐harvesting range due to the photovoltaic effect of PD‐OPDs.…”

Highly sensitive broadband photomultiplication type all-polymer photodetectors and their applications in optical pulse counting

“…[1][2][3] Photomultiplication type PPDs (PM-PPDs) have emerged as the research hotspot in recent years, exhibiting the prominent advantages such as high-sensitivity, low-power consumption and tunable spectral-response-range. [4][5][6] PM-PPDs can be obtained on the basis of active layers possessing single charge carrier transport channels, which were firstly reported by Zhang's group. [7][8][9] The weight difference between the donor and the acceptor is dozens of times in active layers of PM-PPDs, which prefer to form some isolated traps for one kind of charge and also retain continuous transport channels for the opposite charge.…”

Transient analysis of photomultiplication-type organic photodiodes

“…[12][13][14][15][16][17] More recently, photomultiplication-type (PM-type) OPDs have presented extremely high external quantum efficiency (EQE) and responsivity, which is very attractive for weak light detection without pre-amplification and could potentially overcome the conventional charge transport limited low detectivity of OPDs. [18][19][20][21][22][23] In 2008, Chen and co-workers combined CdTe nanoparticles with OPDs and realized high photoconductive gain based on the diode structure. 24 Later on, Guo et al reported multiplication-type OPDs based on interfacial trap-controlled charge injection, and achieved ultraviolet photodetectors with ultrahigh responsivity.…”