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Broadband photomultiplication type all-polymer photodetectors with the structure of ITO/PFN-Br/PBDB-T : PYF-T-o (3 : 100)/LiF/Au achieve EQEs of 18 000% at 360 nm and 9000% at 850 nm under 4 V, which are applied in an optical pulse counting circuit.

Three polymers, DCP1-3, with PC61BM pendants as intramolecular traps were carefully synthesized, and they were successfully applied in photomultiplication-type organic photodetectors (PM-OPDs) showing excellent intrinsic stability.

High-field-effect-mobility InSnZnO thin-film transistors (TFTs) are prepared through Al-induced microstructure regularization (AIMR) at an annealing temperature lower to 400 °C. Spherical crystalline particles are distributed throughout the back channel near the Al layer, while an amorphous phase still represents the front channel but with enhanced microstructure ordering. Especially, the packing density is distinctly increased, and oxygen vacancies are largely reduced. The optimized TFT exhibits excellent performance with a steep sub-threshold swing of 0.18 V/dec, a high on/off current ratio of 2.5 × 108, a threshold voltage of −0.21 V, and a small threshold voltage shift of −0.24 V under negative bias stress (−20 V, 3600 s), especially a remarkable field-effect mobility boosted to 53.2 cm2/V s compared to 19.1 cm2/V s for the TFT without the Al layer. After Al removal, the TFT performance shows no obvious degradation, implying good compatibility of the AIMR technique to the current device process.

Comparing with traditional single organic light-emitting device (OLED), the luminance efficiency and lifetime of tandem OLED are significantly improved. Therefore, it is of crucial importance to in depth study the influence of microcavity effect on the performance of top emitting tandem OLED. In this paper, taking the blue organic light emitting device for example, the change rule of optical and electrical properties of top-emitting tandem blue-light device are studied by combining optical simulation with practical experiments. The specific experiment is as follows. The top emitting tandem blue organic light devices are fabricated, in which the two light-emitting layers are located at the first anti node and second anti node, the second anti node and third anti node, and the third anti node and fourth anti node in the optical structure of the device respectively. It is found that the performance of the device is better when the two emitting layers of the top-emitting tandem blue light device are located at the second anti node and third anti node in the optical structure of the device respectively. That is to say, when the current density of the device is 15 mA/cm2, the current efficiency of the device reaches 10.68 cd/A, color coordinate (CIEx, y) of the device is (0.14, 0.05), and the time of the brightness decreases from 100% to 95% in 1091.55 hours, which is likely to be due to the fact that when the cavity length of the device is long, it can not only improve the recombination rate of hole and electron in the first light-emitting unit, weaken the surface plasmon polarition effect, reduce the influence of the fluctuation of the film thickness on the cavity length of the device, but also play a role of wrapping partials to a certain extent, improve the efficiency and prolong the device lifetime. The research results provide an important theoretical and data basis for designing the top-emitting tandem blue light device with high efficiency and long lifetime. In the future, we will continue to systematically and detailedly study the top emitting tandem organic light-emitting devices, which will provide strong support for preparing the laminated devices with high efficiency long-lifetime, and lower cost.

In this paper, we present a 55” UHD AMOLED TV developed at G8.5 using IGZO backplane and tandem white-OLED with COA (color filter on array), which is considered as one of the feasible options for mass production. We also implement the external optical compensation to achieve good display uniformity.

BCE type oxide semiconductor TFTs with high mobility and high photo reliability has been developed using ITZO as a channel material. The mobility was over 25 cm2/Vs and the threshold voltage shifts of BITS were successfully reduced to 0.4V. Furthermore, a 14inch AMOLED plane based on ITZOBCE TFTs was fabricated.

The ESL type IGZO oxide semiconductor TFTs with high Vth uniformity of delta Vth less than 1V, and high reliability has been developed at BOE G8.5 for 55inch AMOLED TVs. The mobility was ~10 cm2/Vs, the threshold voltage (Vth) shifts of BTS were successfully reduced to less than 1V and the Vth shifts of hysteresis were less than 0.1V. Furthermore, 55inch AMOLED TVs based on ESL type IGZO TFTs were produced with external compensation circuits.

We have designed and fabricated the 14-inch RGBW AMOLED using tandem white-OLED with RGB color-filter. In this paper, we also verified the pixel compensation, RGBW conversion, white OLED color-compensation, and optical compensation, and the comparison of RGBW-quad and RGBW-stripe on this panel.

Low hydrogen dielectric film deposition method was used in PECVD. The properties of amorphous IGZO (a-IGZO) bottom-gate thin film transistor using this method were investigated and compared. The PBTS (Positive Bias Temperature Stress) and NBTS (Negative Bias Temperature Stress) reduced to 0.481V, and -0.269V, respectively. The overall properties of a-IGZO TFT using low hydrogen dielectric recipe meet the demand of oxide backplane in both LCD and OLED field.

TFTs with zinc oxynitride (ZnON) as active layer were developed, and a saturation mobility over 50 cm2/Vs was achieved. The ZnON TFTs show superior I-V performance and Vth uniformity. A 14 inch WOLED panel driven by ZnON TFT was demonstrated. The reliability of ZnON panels was evaluated at high-temperatureoperation and low-temperature-operation conditions, and satisfied results were achieved.

Both etch stopped and back channel etched structure TFTs with zinc oxynitride(ZnON) as active layer were developed, and the saturation mobility achieved 33 cm2/Vs. The ZnON TFTs show superior positive gate bias stress under dark and light illumination. Furthermore, a 5 inch WOLED panel driven by ZnON TFT was demonstrated.

Organic thin-film transistors (OTFTs) with bottom-gate and bottom-contact configuration based on copper phthalocyanines (CuPc) as active layer were fabricated. The performance of CuPc OTFTs was studied before and after thermal treatment on CuPc layer. The values of the threshold voltage before and after thermal treatment are −6.3 and −5.7 V, respectively. The field-effect mobility values in saturation regime of CuPc thin-film transistors before and after thermal treatment are 0.014 cm 2 /Vs and 0.0068 cm 2 /Vs, respectively. The experimental results indicate that there is a heavy decay on the mobility of CuPc based OTFTs mostly due to the crystalline morphology change induced by the thermal treatment, and absolute value of the threshold voltage after thermal treatment decreases with the decrease of the CuPc film thickness and the roughness.

Phenyltrimethoxysilane was used to modify SiO 2 insulator and significantly enhanced the pentacene based organic thin-film transistors (OTFTs). The crystal structure, surface morphology, molecular structure and microstructure of pentacene polymorphic films with and without the modifications were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM) and contact angle meter. XRD studies reveal a decreased tilt angle ( θ T ) of pentacene molecules from c -axis toward a -axis, indicating that polymorphs transformation from the “triclinic bulk” phase to the “thin film” phase and orthorhombic phase occurs. AFM images show that the surface roughness of gate insulators has no influence on performance of the pentacene based OTFT. These results provide strong evidence that the performance improvement of OTFT after PhTMS modification of SiO 2 insulator surface is related to the microstructure transformation of the semiconductor. It suggests that the modified-layer may alter the molecular geometry and further induce structural phase transitions in the pentacene films for the performance improvement.

To investigate the effect of composition of SiNx on the properties of organic thin-film transistors (OTFTs), we fabricated bottom gate top contact OTFTs devices with different composition SiNx gate insulator. Pentacene based OTFTs with SiNx insulator, prepared using an interface modification process of UV-ozone treatment, exhibited effective mobility of 0.63 cm2/Vs and on/off current ratio of 105. Overall improvement in field-effect mobility, threshold voltage was observed as silicon content in SiNx increases. The results demonstrate that the viability of using SiNx for OTFTs and of UV-ozone treatment could be used to improve the properties of organic thin-film transistors. The dependence of the contact angle on the SiNx film composition is evident for the untreated samples, the contact angle increases as the silicon content in the untreated nitride film increases. In contrast, the rise in contact angle across all samples after surface treatment signifies effective surface modification to promote hydrophobicity of the nitride surface. The hydrophobic surface is needed for the organic semiconductor.

Three kinds of organic light emitting diodes with tris(8-hydroxyquinoline) aluminum (Alq 3 ) as emitting layers were fabricated. It was found that the current efficiency (8.2 cd/A) of devices with pentacene as hole transporting layer (HTL) was obtained at 10 V, which was increased by a factor of 3.2 in comparison with that (2.6 cd/A) of the devices with N , N ′-bis-(1-naphthyl)- N , N ′-1-diphenyl-1,1′-biphenyl-4,4′-diamine (NPB) as HTL. The improvement was attributed to the large hole mobility of pentacene and the increased interfacial surface area induced by its pyramid-like morphology, which result in the increase of the recombination region at the interfaces between pentacene and Alq 3 layers. Investigation by atomic force microscopy (AFM) shows the surface morphology of pentacene and NPB thin films.

The influence of evaporation conditions of organic semiconductor material tris(8-hydroxyquinoline)aluminium (Alq3) on the performance of organic light emitting diodes (OLEDs) is reported. In the process of organic material thermal evaporation, the chamber was dark or had white light from a 100 W filament lamp. The devices prepared in the dark show higher emission intensity and efficiency compared with the ones prepared in white light under the same driving voltage. Atomic force microscopy measurements show that surface morphology and phase of Alq3 thin films are quite different for the previous cases. The different evaporation conditions are found to have direct effects on the electrical and luminance performance. The Alq3 thin films prepared in the dark as active emission layers of OLEDs show higher intensity and efficiency.

A novel organic electroluminescent device was made with the structure of ITO/PVK: Tb0.5Eu0.5(TTA)3Dipy/BCP/Alq3/Al(a) which utilized the rare earth complex Tb0.5Eu0.5(TTA)3Dipy as the emitting layer. When it was driven under a direct electric field, 612 nm emission from Eu3+ and 410 nm emission from PVK were observed. In addition, in the EL spectrum a new peak at 490 nm appeared. From the analysis of different devices, the mechanism of the new emission was studied. It was concluded that the new emission was the electroplex originating from the interface between the ligand (TTA)3Dipy and BCP.

Electroluminescence (EL) and photoluminescence (PL) spectra of an electron donor, an (poly(N-vinylcarbazole) (PVK))/electron acceptor, and a (2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD)) bi-layer solid film are analysed. The EL emission peak has an apparent red-shift with the increase of driving voltage. There maybe exist an electroplex emission between the PVK and PBD interface under high electric field strength. According to their energy level, the electroplex emission peak should locate at 460 nm. There are great spectra overlapping between PVK emission and electroplex emission, and the ratio of electroplex emission intensity to exciton emission intensity (Ielectroplex/Iexciton) increases from 0.38 at 10 to 0.81 at 16 V. Therefore the measured emission peaks continuously shift from 410 nm at 10 V to 445 nm at 16 V.

Organic light-emitting diode (OLED) based on two kinds of blue emission materials N,N′-bis(1-naphthyl)-N,N′-diphenyl-l,l′-diphenyl-4,4′-diamine (NPB) and 2-(4-biphenylyl)-5(4-tert-butyl-phenyl)-1,3,4-oxadiazole (PBD) was fabricated. There is only one emission peak in photoluminescence (PL) spectrum which originates from NPB exciton emission. And the electroluminescence (EL) emission peaks have an apparent red-shift with the increase of driving voltage. The red-shift emission from exciplex emission could be ruled out. Thus, by the method of Gaussian fitting it should be ascribed to the overlap of exciton emission and electroplex emission which occurs at the interface between NPB and PBD. The formation of the electroplex emission under high electric field is analyzed.