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A series of BaLa_2－xZnO₅:xTb³⁺ green phosphors were synthesized by solid state reaction, and the structure and luminescence properties of the phosphors were also investigated. The results show that the ternary oxide BaLn₂ZnO₅ has a tetragonal structure with a space group of I4/mcm, and its basic structure consists of LaO₈, BaO₁₀ and ZnO₄ polyhedra. The excitation spectra of the samples are mainly constituted by broadband peak at 241 nm and 279 nm. Under the excitation of 279 nm, the peak of emission spectra was located at 548 nm, which belongs to the f→f transition of Tb³⁺ ions. There exists concentration quenching in BaLa_2－xZnO₅:xTb³⁺ phosphors, when the doping concentration x is more than 0.3. According to Dexter theory, the concentration quenching mechanism of Tb³⁺ in BaLa₂ZnO₄:Tb³⁺ is the d-d interaction.

A new blue phosphorescent iridium(Ⅲ) complex based on 2',6'-difluoro-2,3'-bipyridine and 3-Acetyl-camphor, (dfpypy)₂Ir(acam) was synthesized. The complex emits bright blue phosphorescence with λ_max at 466 nm accompanied a weakly shoulder peak at 487 nm and has the full-width at half maximum (FWHM) of 55 nm. The photoluminescence (PL) quantum yield in degassed THF solution at room temperature is estimated to be 0.51. The efficient non-doped blue phosphorescent electroluminescence devices were fabricated. The structure of devices is ITO/HATCN(1 nm)/TAPC(40 nm)/(dfpypy)₂Ir(acam) (10 nm)/BmpypB (40 nm)/LiF(1 nm)/Al(90 nm). The devices show electroluminescence with λ_max at 474 nm. The devices have V_on value of 3.5 V. At a current density of 20 mA·cm^-2, CIE coordinates are (0.17, 0.29). Maximum brightness of 2 170 cd·m^-2 is achieved at driven voltage of 11 V. At driven voltage of 4.2 V, maximum power efficiency of 5.25 lm·W^-1 and maximum luminance efficiency of 6.45 cd·A^-1 are obtained, respectively.

A preparation process for Al-doped ZnO nanorod arrays by electrodeposition from an aqueous solution of Zn(NO₃)₂, NH₄NO₃ and Al(NO₃)₃ was established. The inevitable growth of the layered nanostructures due to the use of Al(NO₃)₃ was suppressed by the use of NH₄NO₃. Consequently, the use of the additives results in the fabrication of the high quality ZnO nanorod arrays. In addition, the properties of ZnO nanorods such as the diameter, density, distance, and weight ratio of Al/Zn were adjusted by controlling the Al(NO₃)₃ concentration in the electrolyte. The increase of the carrier concentration as a result of Al doping leads to the blue shift of the optical band gap in ZnO nanorods (3.64-3.65 eV), which is ascribed to the Burstein-Moss effect. The Stokes shift of Al-doped ZnO nanorods is in the range of 215-225 meV, indicating a large nonradiative recombination in the nanorods.

By using mental-organic chemical vapor deposition, ZnO films were prepared on sapphire substrate in this work. Three MSM ultraviolet photodetectors with different electrode spacings were fabricated on ZnO films. The detector responsivity achieves marked increase from 15 mA/W to 75 mA/W as the electrode spacing decreases from 150 μm to 5 μm. At the same time, with the decrease of the electrode spacing, I-V curve of the device changes significantly. It is attributed to that the electrode spacing affects the properties of MSM photodetectors because it results in different depletion region width and the resistance between the electrode.

Nano and mirco SrB₆O₁₀·5H₂O:Eu³⁺ with different morphologies were prepared by precipitation method, and they were characterized by EDS, XRD, IR, SEM, their luminescence properties were also studied. The results show that the reaction time has great impacts on the crystallinity, morphology and particle size of the samples. The strongest emission peaks of the samples are all located at 615 nm, exhibiting red emission. The luminous intensity is enhanced with the increasing of reaction time, while the ratio of red to orange increases firstly and then decreases. For the sample with reaction time of 48 h, the emission intensities are similar when it is excited by 391 nm or 250 nm, but the ratio of red to orange excited by 391 nm is higher than that excited by 250 nm, indicating that SrB₆O₁₀·5H₂O:Eu³⁺ is a good near-ultraviolet excited red luminescent material.

TiO₂/Eu³⁺ down-conversion film was prepared by sol-gel method, and its optical and photoelectric properties were analyzed. Applying it to dye-sensitized solar cells (DSSC), partial UV light can be converted to visible light and absorbed by dye according to its down-conversion feature, as thus, the visible light intensity and short circuit currents are improved. The fluorescence spectra show that the down-conversion film can emit 550-640 nm visible light under 394 nm UV light excitation, which indicates a down-conversion feature of the film. The down-conversion film can increase the wavelength range of DSSC absorption. When bilayer down-conversion films are coated on DSSC, the short circuit current increases from 8.05 mA·cm^-2 to 9.62 mA·cm^-2, the photoelectric conversion efficiency increases from 3.67% to 4.32%.

Upright Zn₂GeO₄/ZnO nanorod arrays were prepared on silicon wafer with two kinds of seed layers (metal Au and ZnO seed) by the chemical vapor deposition(CVD) method. Scanning electron microscopy (SEM), X-ray diffractometer (XRD) and photoluminescence (PL) measurements were used to characterize the samples and reaseach its luminescence properties. The results show that the radius of Zn₂GeO₄/ZnO nanorod is 350-400 nm and the length is 10-11 μm. The photoluminescence spectrum (PL) of Zn₂GeO₄ nanorods exhibites three fluorescence emission peaks centered at 415,445,488 nm. Moreover, a detailed description of the probable growth mechanism of the upright Zn₂GeO₄/ZnO nanorod arrays was discussed. Its vertical orientation is desirable for use in optoelectronic field.

Eu³⁺ doped CaWO₄ phosphors were prepared via hydrothermal method. The crystal structures, morphologies and luminescence properties of the powders synthesized at different pH values were characterized by X-ray powder diffraction (XRD), field emission-scanning electron microscopy (FE-SEM) and photoluminescence (PL). The experimental results indicate that CaWO₄:Eu³⁺ particles are hollow spherical shape with good crystallinity, uniform morphology and the diameter about 4 μm when pH of the synthesis solution is higher than 5. Under the excitation of 395 nm ultraviolet light, the emission peaks of CaWO₄:Eu³⁺ phosphor are around 591 nm and 614 nm, which can be attributed to ⁵D₀-⁷F₁,⁵D₀-⁷F₂ transitions of Eu³⁺, respectively. The 614 nm red emission of CaWO₄:Eu³⁺ phosphor is the strongest when pH of the synthesis solution is 5.

In order to reduce the threshold current and obtain the good temperature characteristics of 2 μm InGaAsSb/AlGaAsSb diode laser, AlGaAsSb electronic stopper layer (ESL) was introduced between p-waveguide and p-cladding layer. The research was conducted by LASTIP. The simulated results reveal that ESL can reduce the threshold current and improve the temperature characteristics of LD effectively. All the advantages are due to the lower Auger recombination rate in the quantum wells and smaller electron concentrations in the p-side, which are caused by the higher band offset between ESL and p-waveguide.

The spatio-temporal structures and plasma parameters of the dot-line square superlattice luminous pattern are investigated by using photomultiplier and spectrograph. Optical signals from the discharge filaments show that the dot-line square superlattice pattern is an interleaving of four different transient sub-lattices, three of them occur at the rising edge and one of them at the falling edge in each half voltage-cycle. And the discharge sequence is followed as the small-dot square sub-lattice, the big-dot line sub-lattice, big-dot halo sublattice and the small-dot square sub-lattice located in the center of each big-dot. The emission spectra of the N₂ second positive band (C³Π_u→B³Π_g) are collected and used to calculate the molecular vibration temperatures of the four transient sub-lattices in this pattern. Measurements show that different sub-lattices almost have the same molecular vibration temperature. The influence of the wall charge distribution on the formation process and the spatio-temporal dynamics of the dot-line square superlattice pattern are discussed. It is found that wall charges deposited on the dielectric surface have a great influence on discharge process.

A temperature sensor based on the temperature characteristics of photoluminescence (PL) of CdSe/ZnS core-shell quantum dots (QDs) thin film was designed and fabricated. The results show that PL of CdSe/ZnS QDs thin film changes regularly with the temperature increasing in the range of 30~160 ℃. The self-reference peak intensity of PL decreases with the temperature increasing, while their peak wavelength and full width at half maximum (FWHM) increase. Moreover, the temperature characteristics of self-reference peak intensity, peak wavelength, and FWHM are respectively obtained by fitting one, one and two times fitting function relations. The corresponding correlation indexes R² are all above 96.6%. The temperature sensitivity of peak wavelength is 0.06 nm/℃, and the resolution is about 0.1 ℃. Besides, the temperature detecting by self-reference peak intensity is more stable and accuracy than that only by peak intensity.

The possibility of ZnS:Ag-Al film as highly efficiency electron transfer layer (ETL) was analyzed, and the Bohr radius of impurity atoms was calculated by using quantum theory. The best efficient thickness of theoretical reference value was given for the Ag-Al co-doped ZnS as ETL. The organic light-emitting devices (OLEDs) which use the Ag-Al co-doped ZnS film as ETL were fabricated with the structure of ITO/NPB/Alq₃/ZnS:Ag-Al(x)/PBD/Al. The effect of Ag-Al co-doped ZnS ETL thickness to the characters of OLEDs were investigated in experiments. It is shown that the relative luminescence intensity and electroluminescence intensity of device with co-doped ZnS ETL (8 nm) increase by 430 times and 130 times respectively as compared to device without ETL. Besides, the turn-on voltage is reduced about 4 V. Comparing with OLED with un-doped ZnS ETL, the relative luminescence intensity of Ag-Al co-doped ZnS ETL devices was enhanced by 3 times. The studied results reveal that Ag-Al co-doped ZnS behaves ideal proprieties of electrons transporting and hole blocking properties. Thus it can be expected that Ag-Al co-doped ZnS could be used as other organic photo-electronic devices.

In order to meet the requirements of laboratory radiometric calibration for continually rising optical aperture of optical remote sensors, a calibration source of high luminance with integrating sphere was designed based on Jones method. The integrated radiance in the range of 400 nm to 900 nm was 6 800 W/(m²·sr). The thermal design results indicated that the water-cooling method could meet the heat dissipation of the high luminance calibration source. The integrated radiance of the high luminance calibration source was 6 714 W/(m²·sr) in the range of 400 nm to 900 nm. The temperature distribution of the integrating sphere made the calibration demands satisfied through water-cooling, which suggested that the calibration source of high luminance using integrating sphere based on Jones method could be used to engineering practice.

Yb³⁺-doped CaWO₄ thin films were prepared by radio frequency (RF) magnetron sputtering and the influence of different deposition pressures and time on the structure, surface morphology and optical properties of films were discussed. XRD results confirm that the samples have a tetragonal scheelite structure and the films have a preferential orientation along the (004) direction under different deposition pressures. SEM images show that the surface morphology of the film consists of spherical-like grains and voids. PL spectra indicate that the films emit strong near infrared light centered at 994 nm under 260 nm excitation. The luminescence intensity of Yb³⁺ trends to irregular with the increasing of sputtering pressure, and firstly increases and then decreases with the increasing of sputtering time. Excellent luminescence properties of CaWO₄:Yb³⁺ thin film might be regarded as a potential luminescence converter layer for enhanced silicon solar cell performance.

Thieno thiophene/benzodithiophene (PTB7) and -phenyl C71-butyric acid methyl ester (PC₇₁BM) were selected as donor and acceptor, respectively. The device architecture was glass/ITO/poly(ethylenedioxythiophene):polystyrene sulphonate (PEDOT:PSS)/PTB7: PC₇₁BM/electron extraction layer (EEL)/aluminum. For comparison, tris (8-hydroxyquinoline) aluminum (Alq₃) and calcium (Ca) were used as EEL to reveal their influence on the performance (power conversion efficiency (PCE), short-circuit current density (J_SC), open-circuit voltage (V_OC), and fill factor (FF)) of the OPVs. As a result, PCE of the device with Ca as EEL rapidly reduced over 60% after three days due to the poor stability of Ca. The device with Alq₃ as EEL showed favorable stability owing to the PCE moderate declined less than 30% after one month. Furthermore, PCE of the device with Alq₃ as EEL was fully comparable to that with Ca as EEL. Our results indicate that Alq₃ is an alternative candidate for high-performance and long-term photo-stability OPVs.

Polymer light-emitting diodes (PLEDs) with device structure of indium tin oxide (ITO)/poly(3,4-ethylenedioxylenethiophene):poly(styrenesulphonic acid) (PEDOT:PSS)/emissive layer/tris(8-hydroxyquinolinato)aluminum (Ⅲ) (Alq₃)/lithium fluoride (LiF)/Al were fabricated by solution procedures to obtain highly efficient saturated red electrophosphorescence. In the emissive layer, the blends of poly(9,9-dioctylfluorene) (PFO) and 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PBD) were used as host materials (the mass fraction of PBD was 30%), and the iridium complexes Ir-1 and Ir-2 were used as the guest materials. The electroluminescent properties were investigated by changing the doping mass fraction of the iridium complexes in the emissive layer from 1% to 8%. The luminous efficiencies of PLEDs with Ir-1 and Ir-2 enhance when the dopant mass fraction increases from 1% to 2%. A further increase of the dopant mass fraction from 2% to 8% results in a decrease of the maximum luminous efficiencies, as a result of the concentration quenching and triplet-triplet (T-T) annihilation. The highest luminous efficiency of 2.72 cd·A^-1 using Ir-1 as dopant is obtained at the doping mass fraction of 2%, and the luminous efficiency reduces to 2.17 cd·A^-1 at a higher current density of 100 mA·cm^-2. Contrastively, the device based on Ir-2 exhibits highest luminous efficiency of 2.78 cd·A^-1 at doping mass fraction of 2%. In addition, the luminous efficiency still stays at 2.30 cd·A^-1 as the current density rises to 100 mA· cm^-2. Compared to Ir-1 which containing phenyl group in its ancillary ligand, Ir-2 with triphenylamine-modified ancillary ligand displays better electroluminescent performances, probably due to the triphenylamine group has bigger steric hindrance which can efficiently suppress concentration quenching and T-T annihilation. This indicates that it is an effective method to develop highly efficient electrophosphorescent devices by introducing big steric hindrance and good charge transport group into the ancillary ligand of the iridium complex.

Doxycycline can coordinate with europium (Ⅲ) to form EuDC complex which emits characteristic fluorescence peak of europium (Ⅲ). The fluorescence of EuDC complex can be further enhanced by silver nanoparticles through the metal-enhanced fluorescence effect. This method was applied to determine the doxycycline content in duck egg white in this essay. Firstly, 390 nm and 617 nm were selected as the optimum excitation wavelength and emission wavelength by using three-dimensional fluorescence spectrometry. Secondly, the optimum experiment conditions were determined by single factor experiment under the optimum excitation wavelength. Finally, the samples of concentration range of 0.5~30 mg/L were analyzed, and the fluorescence intensity displayed a good linear relationship to the doxycycline concentrations in duck egg white with a detection limit of 0.5 mg/L. The experiment results indicate that the method of silver nanoparticles enhanced fluorescence of europium (Ⅲ) can achieve the rapid determination of doxycycline content in duck egg white.

A photonic crystal waveguide structure with two-dimensional triangular lattice photonic crystals is proposed, in which emission efficiency can be enhanced. The composite structure is composed by cascading a coupled waveguide arrays to a single waveguide. The emission characteristics of light are analyzed via the finite-difference time-domain(FDTD)method. The results show that the emission efficiency of the cascading composite structure is improved. The device has been optimized further. When the distance between the single waveguide and the waveguide arrays is 1.8a, the horizontal and vertical period number of the waveguide arrays are 6 and 5, the emission efficiency is the best. The emission efficiency is over 20%, when the distance is 100a between the waveguide output and detector. This type structure of photonic crystal has potential applications in near-field optics and integrated optics.

The problem of OLED current decrease with threshold voltage (V_th) shift of a-IGZO TFTs still remains to be solved. In this paper, we continued to investigate the compensation effect for V_th shift in AMOLED pixel circuits based on a-IGZO TFTs. With the device models extracted from the experimental data on a-IGZO TFTs prepared in our lab, two kinds of pixel circuits, i.e 2T1C and 4T1C were comparatively studied. The results show that 4T1C pixel circuit has excellent compensation effect for bias-stress instability, and the increasing storage capacitor and W/L of driving TFTs might lead to better holding capacity of this circuit.

The enhanced cooling models based on thermoelectric effect were presented to meet the thermal demand of high-power LED headlight. The cooling performance of different device was evaluated and compared through measuring the LED case temperature. It is found that the thermoelectric cooler is more sensitive to the external fan speed than the purely enforced air cooler. In addition, the optimal drive currents for the model one (air cooling+TEC) and model two (liquid cooling+TEC) are 3 A and 5 A, respectively. When the ambient temperature within its limit level (60-65 ℃), the junction temperature can be calculated to be 55.5℃, and the output light is 1 458.8 lm.

A patterned board configuration for light-emitting diode chip-on-board devices (LED COBs) with regular concave structures on it was presented. Optical models of LED chip and the phosphor were presented, and a Monte Carlo ray-tracing simulation procedure was used to simulate the light emission process. The inclination angle of the concave was the controlling parameter. The results show that the patterned board can not only improve the light extraction efficiency but also the angular color uniformity (ACU) of LED. When the inclination angles α=25°, simulations show a maximum 66.2% and 73.6% light extraction efficiency improvement for this configuration compared with the conventional configuration, respectively. Without the pattern, the ACU of LED are 0.695 and 0.777 for planar board and for the board with reflecting cups, respectively. While with the pattern, the ACU are 0.799 and 0.814, respectively, when α=30°.