Colloidal quantum dots(CQDs)are affected by the quantum confinement effect,which makes their bandgap tunable.This characteristic allows these materials to cover a broader infrared spectrum,providing a costeffective al...Colloidal quantum dots(CQDs)are affected by the quantum confinement effect,which makes their bandgap tunable.This characteristic allows these materials to cover a broader infrared spectrum,providing a costeffective alternative to traditional infrared detector technology.Recently,thanks to the solution processing properties of quantum dots and their ability to integrate with silicon-based readout circuits on a single chip,infrared detectors based on HgTe CQDs have shown great application prospects.However,facing the challenges of vertically stacked photovoltaic devices,such as barrier layer matching and film non-uniformity,most devices integrated with readout circuits still use a planar structure,which limits the efficiency of light absorption and the effective separation and collection of photo-generated carriers.Here,by synthesizing high-quality HgTe CQDs and precisely controlling the interface quality,we have successfully fabricated a photovoltaic detector based on HgTe and ZnO QDs.At a working temperature of 80 K,this detector achieved a low dark current of 5.23×10^(-9)A cm^(-2),a high rectification ratio,and satisfactory detection sensitivity.This work paves a new way for the vertical integration of HgTe CQDs on silicon-based readout circuits,demonstrating their great potential in the field of high-performance infrared detection.展开更多
The lattice-matched XBn structures of InAsSb,grown on GaSb substrates,exhibit high crystal quali⁃ty,and can achieve extremely low dark currents at high operating temperatures(HOT).Its superior performance is attribute...The lattice-matched XBn structures of InAsSb,grown on GaSb substrates,exhibit high crystal quali⁃ty,and can achieve extremely low dark currents at high operating temperatures(HOT).Its superior performance is attributed to the unipolar barrier,which blocks the majority carriers while allowing unhindered hole transport.To further explore the energy band and carrier transport mechanisms of the XBn unipolar barrier structure,this pa⁃per systematically investigates the influence of doping on the dark current,photocurrent,and tunneling character⁃istics of InAsSb photodetectors in the PBn structure.Three high-quality InAsSb samples with unintentionally doped absorption layers(AL)were prepared,with varying p-type doping concentrations in the GaSb contact layer(CL)and the AlAsSb barrier layer(BL).As the p-type doping concentration in the CL increased,the device’s turn-on bias voltage also increased,and p-type doping in the BL led to tunneling occurring at lower bias voltages.For the sample with UID BL,which exhibited an extremely low dark current of 5×10^(-6) A/cm^(2).The photocurrent characteristics were well-fitted using the back-to-back diode model,revealing the presence of two opposing space charge regions on either side of the BL.展开更多
基金Supported by National Key Research and Development Program in the 14th five year plan(2021YFA1200700)Strategic Priority Re⁃search Program of the Chinese Academy of Sciences(XDB0580000)Natural Science Foundation of China(62025405,62104235,62105348).
文摘Colloidal quantum dots(CQDs)are affected by the quantum confinement effect,which makes their bandgap tunable.This characteristic allows these materials to cover a broader infrared spectrum,providing a costeffective alternative to traditional infrared detector technology.Recently,thanks to the solution processing properties of quantum dots and their ability to integrate with silicon-based readout circuits on a single chip,infrared detectors based on HgTe CQDs have shown great application prospects.However,facing the challenges of vertically stacked photovoltaic devices,such as barrier layer matching and film non-uniformity,most devices integrated with readout circuits still use a planar structure,which limits the efficiency of light absorption and the effective separation and collection of photo-generated carriers.Here,by synthesizing high-quality HgTe CQDs and precisely controlling the interface quality,we have successfully fabricated a photovoltaic detector based on HgTe and ZnO QDs.At a working temperature of 80 K,this detector achieved a low dark current of 5.23×10^(-9)A cm^(-2),a high rectification ratio,and satisfactory detection sensitivity.This work paves a new way for the vertical integration of HgTe CQDs on silicon-based readout circuits,demonstrating their great potential in the field of high-performance infrared detection.
基金Supported by the Candidate Talents Training Fund of Yunnan Province(202205AC160054)the National Natural Science Foundation of China(62174156)。
文摘The lattice-matched XBn structures of InAsSb,grown on GaSb substrates,exhibit high crystal quali⁃ty,and can achieve extremely low dark currents at high operating temperatures(HOT).Its superior performance is attributed to the unipolar barrier,which blocks the majority carriers while allowing unhindered hole transport.To further explore the energy band and carrier transport mechanisms of the XBn unipolar barrier structure,this pa⁃per systematically investigates the influence of doping on the dark current,photocurrent,and tunneling character⁃istics of InAsSb photodetectors in the PBn structure.Three high-quality InAsSb samples with unintentionally doped absorption layers(AL)were prepared,with varying p-type doping concentrations in the GaSb contact layer(CL)and the AlAsSb barrier layer(BL).As the p-type doping concentration in the CL increased,the device’s turn-on bias voltage also increased,and p-type doping in the BL led to tunneling occurring at lower bias voltages.For the sample with UID BL,which exhibited an extremely low dark current of 5×10^(-6) A/cm^(2).The photocurrent characteristics were well-fitted using the back-to-back diode model,revealing the presence of two opposing space charge regions on either side of the BL.
