Meng Zhiguo

Tricolor microcavity OLEDs based on P-nc-Si:H films as the complex anodes

A P + -nc-Si:H film (boron-doped nc-Si:H thin film) was used as a complex anode of an OLED. As an ideal candidate for the composite anode, the P + -nc-Si:H thin film has a good conductivity with a high work function (∼ 5.7 eV) and outstanding optical properties of high reflectivity, transmission, and a very low absorption. As a result, the combination of the relatively high reflectivity of a P + -nc-Si:H film/ITO complex anode with the very high reflectivity of an Al cathode could form a micro-cavity structure with a certain Q to improve the efficiency of the OLED fabricated on it. An RGB pixel generated by microcavity OLEDs is beneficial for both the reduction of the light loss and the improvement of the color purity and the efficiency. The small molecule Alq would be useful for the emitting light layer (EML) of the MOLED, and the P + -nc-Si film would be used as a complex anode of the MOLED, whose configuration can be constructed as Glass/LTO/P + -nc-Si:H/ITO/MoO3/NPB/Alq/LiF/Al. By adjusting the thickness of the organic layer NPB/Alq, the optical length of the microcavity and the REB colors of the device can be obtained. The peak wavelengths of an OLED are located at 486, 550, and 608 nm, respectively. The CIE coordinates are (0.21, 0.45), (0.33, 0.63), and (0.54, 0.54), and the full widths at half maximum (FWHM) are 35, 32, and 39 nm for red, green, and blue, respectively.

Design for SOP AMOLED display panel

A novel full color SOP (system on panel) AMOLED display based on the MIUC polycrystalline silicon TFT technique, and a new control circuit for the panel, which can deal with both VGA and DVI input signals have been developed. To realize gray-scale a sub-frame technique has been designed and implemented by FPGA device, in which an I2C module has been inserted. Through actual circuit, the whole design has been proven and the advantages of the SOP AMOLED display panel have been confirmed.

The mechanism of hydrogen plasma passivation for poly-crystalline silicon thin film

The mechanism of hydrogen plasma passivation for poly-crystalline silicon (poly-Si) thin films is investigated by optical emission spectroscopy (OES) combined with Hall mobility, Raman spectra, absorption coefficient spectra, and so on. It is found that different kinds of hydrogen plasma radicals are responsible for passivating different defects in poly-Si. The H? with lower energy is mainly responsible for passivating the solid phase crystallization (SPC) poly-Si whose crystallization precursor is deposited by plasma-enhanced chemical vapor deposition (PECVD). The H* with higher energy may passivate the defects related to teh Ni impurity around the grain boundaries more effectively. In addition, H? and H? with the highest energy are required to passivate intra-grain defects in the poly-Si crystallized by SPC but whose precursor is deposited by low pressure chemical vapor deposition (LPCVD).

Dynamic Ni gettered by PSG from S-MIC poly-Si and its TFTs

A dynamic phosphor-silicate glass (PSG) gettering method is proposed in which the processes of the gettering of Ni by PSG and the crystallizing of α-Si into poly-Si by Ni take place simultaneously. The effects of PSG gettering process on the performances of solution-based metal induced crystallized (S-MIC) poly-Si materials and their thin film transistors (TFTs) are discussed. The crystallization rate is much reduced due to the fact that the Ni as a medium source of crystallization is extracted by the PSG during crystallization at the same time. The boundary between two neighbouring grains in S-MIC poly-Si with PSG looks blurrier than without PSG. Compared with the TFTs made from S-MIC poly-Si without PSG gettering, the TFTs made with PSG gettering has a reduced gate induced leakage current.