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We report a high-performance colloidal quantum dot (CQD)-based near-infrared tandem photodetector fabricated on flexible substrates via solution-processed method. The tandem photodetector on poly(ethylene terephthalate) substrates exhibited low dark current and high detectivities over ∼8.8×1011 Jones at near infrared range at -0.5V bias and over ∼1013 Jones near 0 bias. The critical bend radii of ∼8mm and ∼3mm have been demonstrated for tensile and compressive bending, respectively. The performance of photodetectors remains stable under mechanical stress, making PbSe CQD material a promise candidate for flexible infrared sensing applications. [ABSTRACT FROM AUTHOR]

In an attempt to suppress the dark current, the barrier layer engineer for solution-processed PbSe colloidal quantum-dot (CQD) photodetectors has been investigated in the present study. It was found that the dark current can be significantly suppressed by implementing two types of carrier blocking layers, namely, hole blocking layer and electron blocking layer, sandwiched in between two active PbSe CQD layers. Meanwhile no adverse impact has been observed for the photo current. Our study suggests that this improvement resides on the transport pathway created via carrier recombination at intermediate layer, which provides wide implications for the suppression of dark current for infrared photodetectors. [ABSTRACT FROM AUTHOR]