Operating at room temperature, polymer photodetectors (PDs) with external quantum efficiency approximately 80%, detectivity over 10(13) Jones, linear dynamic range over 120 dB, and dark current a few decades of nA/cm(2) were demonstrated. All these performance parameters were achieved by combined treatment of active layer with solvent vapor annealing and of polymer PDs with postproduction thermal annealing. These high performance parameters demonstrated that polymer PDs is comparable to or better than inorganic counterparts.

In this paper we study the existence and multiplicity of the solutions for the fourth-order boundary value problem (BVP) u (4) η ∈ R and λ ∈ R + are parameters. By means of the idea of the decomposition of operators shown by Chen [W.Y. Chen, A decomposition problem for operators, Xuebao of Dongbei Renmin University 1 (1957) 95-98], see also [M. Krasnosel'skii, Topological Methods in the Theory of Nonlinear Integral Equations, Gostehizdat, Moscow , 1956], and the critical point theory, we obtain that if the pair (η, ζ ) is on the curve ζ = −η 2 /4 satisfying η < 2π 2 , then the above BVP has at least one, two, three, and infinitely many solutions for λ being in different interval, respectively.

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We report the fabrication of high-performance broadband polymer photodetectors based on narrow bandgap conjugated polymers with an inverted device structure, where electrons and holes are collected on indium tin oxide and metal contact with high work function. High-quality wide bandgap vertically aligned ZnO nanowire array offers an enhanced surface area and is used as the cathode buffer layer in this device for effectively extracting electrons and blocking holes from the active polymer layer. The room-temperature detectivity of polymer photodetectors with such an inverted device structure is greater than 10 10 Jones with the spectral response from 400 to 1450 nm. Our results define a promising pathway for fabrication of high-sensitivity polymer photodetectors with an inverted device structure using ZnO nanowire array cathode buffer layer for a wide range of applications.

Water-soluble cadmium telluride (CdTe) quantum dots (QDs) used as an anode interlayer in solution-processed near infrared (NIR) polymer photodetectors (PDs) were demonstrated. Polymer PDs incorporated with CdTe QDs as an anode interlayer exhibited 10-fold suppressed dark current density and analogous photocurrent density relative to poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), which resulted in enhanced detectivities over 10(11) Jones in the spectral range from 350 nm to 900 nm. Moreover, with the substitution of PEDOT:PSS by CdTe QDs, the stability of unencapsulated NIR polymer PDs was extended up to 650 hours, which is more than 3 times longer than those with PEDOT:PSS as an anode interlayer. These results indicated that CdTe QDs can be utilized as a solution-processable alternative to PEDOT:PSS as an anode interlayer for high performance NIR polymer PDs.