A monolithic integrated medium wave Mercury Cadmium Telluride polarimetric focal plane array

A medium wave(MW)640×512(25μm)Mercury Cadmium Telluride(HgCdTe)polarimetric focal plane array(FPA)was demonstrated.The micro-polarizer array(MPA)has been carefully designed in terms of line grating structure optimization and crosstalk suppression.A monolithic fabrication process with low damage was explored,which was verified to be compatible well with HgCdTe devices.After monolithic integration of MPA,NETD<9.5 mK was still maintained.Furthermore,to figure out the underlying mechanism that dominat⁃ed the extinction ratio(ER),specialized MPA layouts were designed,and the crosstalk was experimentally vali⁃dated as the major source that impacted ER.By expanding opaque regions at pixel edges to 4μm,crosstalk rates from adjacent pixels could be effectively reduced to approximately 2%,and promising ERs ranging from 17.32 to 27.41 were implemented.

Electron beam evaporation deposition of cadmium sulphide and cadmium telluride thin films: Solar cell applications

Cadmium sulphide （CdS） and cadmium telluride （CdTe） thin films are deposited by electron beam evaporation. Atomic force microscopy （AFM） reveals that the root mean square （RMS） roughness values of the CdS films increase as substrate temperature increases. The optical band gap values of CdS films increase slightly with the increase in the substrate temperature, in a range of 2.42-2.48 eV. The result of Hall effect measurement suggests that the carrier concentration decreases as the substrate temperature increases, making the resistivity of the CdS films increase. CdTe films annealed at 300 ℃ show that their lowest transmittances are due to their largest packing densities. The electrical characteristics of CdS/CdTe thin film solar cells are investigated in dark conditions and under illumination. Typical rectifying and photovoltaic properties are obtained.

Experimental investigation on indoor daylight environment of building with Cadmium Telluride photovoltaic window

Photovoltaic(PV)windows have received more and more attention in recent years since their active energy-saving advantages.Considering the surface covered with solar cell modules,the indoor daylight environment of PV windows is obviously different with clear glass windows.However,despite many scholars have studied the indoor daylight environment of PV windows,there few investigations study it from the perspective of human subjective visual perception.In this paper,the indoor daylight environment and human visual comfort of building with Cadmium Telluride Photovoltaic(CdTe-PV)window were investigated.Firstly,the parameters of indoor daylight environment and subjective questionnaires in rooms with CdTe-PV window and clear glass window were analyzed respectively.On the basis of this,combined with indoor working surface illuminance and results of subjective questionnaires,the daylight illuminance threshold of human visual comfort was investigated by the method of Mean Bias Degree(MBD).Finally,an evaluation model for indoor daylight environment of buildings with CdTe-PV window was developed by Fuzzy Comprehensive Evaluation Method.The results showed that the working surface illuminance of CdTe-PV window was lower than that of clear glass room,the CCT of different windows room had a minor gap and the CdTe-PV window room was closer to the recommended range that was 3300-5000K.As for CRI,both the CdTe-PV window room and the clear glass room could meet the visual comfort requirements of office staff.Furthermore,it was found that the requirement of human visual comfort was met when indoor working surface illuminance varies between 500-2200lx in the room with CdTe-PV window.At last,according to the comprehensive evaluation model proposed in this paper,it was found that the indoor daylight environment of buildings with CdTe-PV window was excellent in the present experiment.

Biosynthesis of Biocompatible Cadmium Telluride Quantum Dots Using Yeast Cells

We demonstrate a simple and efficient biosynthesis method to prepare easily harvested biocompatible cadmium telluride(CdTe)quantum dots(QDs)with tunable fluorescence emission using yeast cells.Ultraviolet-visible(UV-vis)spectroscopy,photoluminescence(PL)spectroscopy,X-ray diffraction(XRD),and transmission electron microscopy(TEM)confirm that the CdTe QDs are formed via an extracellular growth and subsequent endocytosis pathway and have size-tunable optical properties with fluorescence emission from 490 to 560 nm and a cubic zinc blende structure with good crystallinity.In particular,the CdTe QDs with uniform size(2-3.6 nm)are protein-capped,which makes them highly soluble in water,and in situ bio-imaging in yeast cells indicates that the biosynthesized QDs have good biocompatibility.This work provides an economic and environmentally friendly approach to synthesize highly fluorescent biocompatible CdTe QDs for bio-imaging and bio-labeling applications.

Higher open-circuit voltage set by cobalt redox shuttle in SnO_2 nanofibers-sensitized CdTe quantum dot solar cells

In this study, we report an efficient CdTe-SnOquantum dot（QD） solar cell fabricated by heat-assisted drop-casting of hydrothermally synthesized CdTe QDs on electrospun SnOnanofibers. The as-prepared QDs and SnOnanofibers were characterized by dynamic light scattering（DLS）, UV–Vis spectroscopy,photoluminescence（PL） spectra, X-ray diffraction（XRD） and transmission electron microscopy（TEM）. The SnOnanofibers deposited on fluorine-doped tin oxide（SnO） and sensitized with the CdTe QDs were assembled into a solar cell by sandwiching against a platinum（Pt） counter electrode in presence of cobalt electrolyte. The efficiency of cells was investigated by anchoring QDs of varying sizes on SnO. The best photovoltaic performance of an overall power conversion efficiency of 1.10%, an open-circuit voltage（Voc）of 0.80 V, and a photocurrent density（JSC） of 3.70 m A/cmwere obtained for cells with SnOthickness of5–6 μm and cell area of 0.25 cmunder standard 1 Sun illumination（100 m W/cm）. The efficiency was investigated for the same systems under polysulfide electrolyte as well for a comparison.

TEC Colling Shortwave Infrared 320×256 Focal Plane Detector

The short-wave HgCdTe thin film material was grown by liquid phase epitaxy on CdTe substrate,Adopt n on p injection bonding and function and flip-flop mixing process,With a low noise readout circuit,sealed with a high airtightness cellular-metal shell,Using a four-stage Thermo Electric Cooler(TEC),320×256 Short Wave Infrared Focal Plane Cooling Detecto r available to operate at near room temperature(210K).Its main photoelectric performance are signal-to-noise ratio greater than 400,nonuniformity equivalent to 4.69%,operability equivalent to 99.76%,frame rate equivalent to 115Hz,component weight less than 150grams.

Preparation and Performance of CdZnTe Ray Detector

γ-ray and x-ray detectors made by Cd1-xZnxTe alloy can gain high energy resolution and detect efficiency at room temperature due to its high atomic number,large energy gap and high density,which were well-developed recently.By well controlled of Cadmium partial pressure and compensatory doping technique,Ф90 mm Cd1-xZnxTe alloy obtained successfully(ρ≥1011Ω·cm)by an improved-Bridgman method.3 mm×3 mm×3 mm CZT de­tector was made at Kunming Institute of Physics,which has energy resolu­tion of 3.52%(FWHM)at room temperature when detect 59.54 KeV Am241γ-ray source.

Photoelectrochemistry of electrochemically deposited cadmium-rich cadmium mercury telluride films

The potentiostatic deposition of cadmium-rich CMT films onto Ti, Mo, Ni substrates from an aqueous bath was carried out. The photoelectrochemical properties of film electrodes were investigated when used in a solid-liquid junction photoelectrochemical cell (PEC). A.C. capacitance was determined.

A novel visible-light Nd-doped CdTe photocatalyst for degradation of Reactive Red 43:Synthesis,characterization,and photocatalytic properties

Novel high-efficiency visible-light-sensitive Nd-doped CdTe nanoparticles were prepared with various doping concentra- tions of neodymium ion by a facile hydrothermal method. The reaction products were analyzed via X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, photoelectron spectroscopy （XPS）, and UV-Vis diffuse re- flectance spectroscopy techniques. Red shift was seen in the absorption band edge peak in the UV-Vis absorbance specmun with in- creasing Nd content. The XRD and XPS results confirmed that Nd ions successfully replaced Cd atoms and were incorporated into the crystal lattice of CdTe. SEM and TEM images indicated spherical structure and high crystallinity. Even at a very low Nd/CdTe molar ratio of 2 mol.%, Nd doping could greatly enhance the photocatalytic activity of CdTe. The photocatalytic activity of Nd-doped CdTe nanoparticles was evaluated by monitoring the decolorization of RRed 43 in aqueous solution under visible-light irradiation. The color removal efficiency of Nd0.08Cd0.9eYe and pure CdTe were 83.14% and 14.32% after 100 min of treatment, respectively. Among different amounts of the doping agent, 8 tool.% Nd indicated the highest decolorization. The presence of radical scavengers such as CF, CO3-, SO4〉, and huthanol was found to reduce the decolorization efficiency.

An alternative aqueous synthetic route to preparing CdTe quantum dots with tunable photoluminescence

An aqueous synthetic route has been developed for the preparation of mercaptosuccinic acid（MSA）-capped CdTe quantum dots （QDs） using TeO_2 as tellurium source and sodium borohydride as reductant.The size and the emission color of CdTe QDs can be tuned by varying the reflux time.The obtained QDs were characterized by photoluminescence（PL） spectroscopy,X-ray powder diffraction（XRD） and high-resolution transmission electron microscopy（HRTEM）.The results show that the CdTe QDs were of zinc-blende crystal structure in a sphere-like shape.

Intensifying process of polarization effect within pixellated CdZnTe detectors for X-ray imaging

The intensifying process of polarization effect at room temperature in a pixellated Cadmium zinc telluride （CdZnTe） monolithic detector is studied. The process is attributed to the increase in build up space charges in the CdZnTe crystal, which causes an expansion of the space charge region under the irradiated area. The simulations of electric potential distributions indicate that the distorted electric potential due to the high X-ray flux is significantly changed and even deteriorated due to increasing space charges within the irradiated volume. An agreement between the space charge distribution and electric potential is discussed.

Photoluminescence of CdTe quantum dots ligated with caprylic acid synthesized at low temperature

Photoluminescent semiconductor nanocrystals or quantum dots(QDs)are usually produced using expensive ligands and solvents at high temperature above 280◦C to ensure high-quality optical properties,particularly the photoluminescence of QDs.The reproducibility of highly stable photoluminescence in QD preparation,in most cases,varies depending on many effects,such as the ligand used and temperature.Here a facile preparation of photoluminescent semiconductor CdTe nanocrystals or quantum dots(QDs)is conducted in the presence of caprylic acid at moderate temperatures between 80–140◦C,which are much lower than the high temperatures used in conventional organic-phase preparation of CdTe QDs.The results show that the optical properties of CdTe QDs depend considerably on the reaction time,temperature and ligand used.

Microwave-assisted Synthesis of CdTe Quantum Dots Using 3-Mercaptopropionic Acid as Both a Reducing Agent and a Stabilizer

In this paper, a facile synthetic approach to prepare CdTe quantum dots（QDs） with high luminescence via a one-pot microwave irradiation reaction route using 3-mercaptopropionic acid（MPA） as both a sodium tellurite re- ducer and a capping molecule was described, and the mechanism of the formation of CdTe QDs was elucidated. In this approach, CdTe QDs with six different emission wavelengths of 553, 567, 577, 595, 608 and 615 nm were ob- tained via changing the refluxing time and the quantum yields（QY） of these QDs were 40.6%, 55.3%, 63.6%, 43.4%, 37.4% and 29.7%, respectively. The characterization results of X-ray powder diffraction（XRD） and transmission electron microscopy（TEM） indicate that the obtained QDs have a pure cubic zinc blended structure with a spherical shape. No toxic gases were released during the preparation process, indicating that the method is relatively fast, cheap and environmentally friendly.