Responsivity

About: Responsivity is a research topic. Over the lifetime, 9918 publications have been published within this topic receiving 186118 citations.

Highly Efficient and Ultrasensitive Large-Area Flexible Photodetector Based on Perovskite Nanowires

Abstract: Hybrid organic-inorganic perovskites have shown exceptional semiconducting properties and microstructural versatility for inexpensive, solution-processable photovoltaic and optoelectronic devices. In this work, an all-solution-based technique in ambient environment for highly sensitive and high-speed flexible photodetectors using high crystal quality perovskite nanowires grown on Kapton substrate is presented. At 10 V, the optimized photodetector exhibits a responsivity as high as 0.62 A W-1 , a maximum specific detectivity of 7.3 × 1012 cm Hz1/2 W-1 , and a rise time of 227.2 µs. It also shows remarkable photocurrent stability even beyond 5000 bending cycles. Moreover, a deposition of poly(methyl methacrylate) (PMMA) as a protective layer on the perovskite yields significantly better stability under ambient air operation: the PMMA-protected devices are stable for over 30 days. This work demonstrates a cost-effective fabrication technique for high-performance flexible photodetectors and opens opportunities for research advancements in broadband and large-scale flexible perovskite-based optoelectronic devices.

Ultrathin Broadband Germanium–Graphene Hybrid Photodetector with High Performance

Abstract: Germanium-based photodetector is a key component in silicon based photonics because of its unique properties of response at telecommunication band and compatibility with CMOS techniques. However, the limitations of low quantum efficiency and high surface recombination in ultrathin germanium film, especially in the near-infrared range, put huge obstructions on the road toward applications. Nowadays, practical applications require more nanoscale devices with lower power consumption as well as higher responsivity and response speed. In this work, we first demonstrate a germanium–graphene hybrid structure photodetector that consists of an ultrathin 20 nm germanium layer and a monolayer graphene. The photodetector can achieve a broadband detection from ultraviolet to near-infrared range. A conductive gain of 155 and a responsivity of 66.2 A W–1 are achieved, which is about 3 orders of magnitude higher than pure graphene photodetectors and about 4 times larger than pure germanium photodetectors. Such enhancemen...

Low-cost uncooled infrared detectors in CMOS process

Abstract: This paper reports the implementation and comparison of two low-cost uncooled infrared microbolometer detectors that can be implemented using standard n-well CMOS processes. One type is based on a suspended n-well resistor, which is implemented in a 0.8 μm CMOS process and has a pixel size of 80 μm ×80 μm with a fill factor of 13%; and the other type is based on a suspended p+-active/n-well diode, which is implemented in a 0.35 μm CMOS process and has a pixel size of 40 μm ×40 μm with a fill factor of 44%. These detectors can be obtained with simple bulk-micromachining processes after the CMOS fabrication, without the need for any complicated lithography or deposition steps. The diode type detector has a measured dc responsivity ( R ) of 4970 V/W at 20 μA bias and a thermal time constant of 35.8 ms at 80 mTorr vacuum level, and it has a measured rms noise of 0.52 μV for a 4 kHz bandwidth, resulting in a detectivity (D∗) of 9.7×108 cm Hz1/2/W. The resistive n-well detector can provide the same dc responsivity at 1.68 V detector bias voltage, with about 10 times more self-heating as compared to that of the diode type detector. This detector has a measured rms noise of 0.81 μV for a 4 kHz bandwidth, resulting in a detectivity (D∗) of 8.9×108 cm Hz1/2/W, which can be improved further with higher detector bias voltages at the expense of increased self-heating. The diode type detector is better for low-cost large format infrared detector arrays, since it has a superior response even at reduced pixel sizes and lower biasing levels.

Compact InAlAs–InGaAs Metal– Semiconductor– Metal Photodetectors Integrated on Silicon-on-Insulator Waveguides

Abstract: We present measurement results of compact and efficient InAlAs-InGaAs metal-semiconductor-metal photodetectors integrated on silicon-on-insulator (SOI) waveguides. These thin-film devices are heterogeneously integrated on the SOI substrate by means of low-temperature die-to-wafer bonding using divinyldisiloxane benzocyclobutene (DVS-BCB). The responsivity of a 30-mum-long detector is 1.0 A/W at a wavelength of 1550 nm and the dark current is 4.5 nA at a bias voltage of 5 V.

A fast and zero-biased photodetector based on GaTe–InSe vertical 2D p–n heterojunction

Abstract: p–n junctions serve as the building blocks for fundamental semiconductor devices, such as solar cells, light-emitting diodes (LEDs) and photodetectors. With recent studies unveiling the excellent optoelectronic properties of two-dimensional (2D) semiconductors, they are considered to be superb candidates for high performance p–n junctions. Here, we fabricate a vertical GaTe–InSe van der Waals (vdWs) p–n heterojunction by a PDMS-assisted transfer technique without etching. The fabricated p–n heterojunction shows gate-tunable current-rectifying behavior with a rectification factor reaching 1000. In addition, it features fast photodetection under zero bias as well as a high power conversion efficiency (PCE). Under 405 nm laser excitation, the zero-biased photodetector shows a high responsivity of 13.8 mA W−1 as well as a high external quantum efficiency (EQE) of 4.2%. Long-term stability is also observed and a response time of 20 µs is achieved due to stable and fast carrier transit through the built-in electric field in the depletion region. Fast and efficient charge separation in the vertical 2D p–n junction paves the way for developing 2D photodetectors with zero dark current, high speed and low power consumption.