Direct monitoring of the recombination zone in highly efficient phosphorescent organic light-emitting diodes based on a high-doping concentration emitting system

The high-content bipolar phosphor (ppy)2Ir(dipba) can dominate the EL process and the recombination zone is almost broadened as wide as the whole EML in D4, leading to remarkably higher efficiency level of D4 than that of D2 based on (ppy)2Ir(acac).

0.97 mΩcm2/820 V 4H-SiC Super Junction V-Groove Trench MOSFET

We have fabricated Super Junction (SJ) V-groove trench MOSFETs (VMOSFETs), demonstrated a low specific on-resistance (RonA) of 0.97 mΩcm2 and a blocking voltage (VB) of 820 V. In the first trial, SJ structure in 4H-SiC have proved to be a good combination with MOS interface on (0-33-8) faces which keep high channel mobility in high doping concentration. We designed a protection structure called “upper p-pillar region” and demonstrated that VB lowering appeared according to its width.

Growth of the Sol-Gel Based ZnO:Al Thin Films with High Doping Concentration

Preferentially oriented Al-doped ZnO thin films with doping concentration of 1, 2, 3, 5 and 10 mol% respectively were prepared on glass substrates via sol-gel route. The crystallinity of films was characterized by X-ray diffraction and the surface morphologies were observed by scanning electron microscopy. The results show that ZnO:Al films at low doping concentration (1, 2 mol%) grow into dense homogenous microstructure. However, as for high doping concentration (3, 5, 10 mol%), Al3+ precipitate in the form of amorphous Al2O3 and ZnO:Al films exhibit heterogeneous nucleation and exceptional growth of the big plate-like crystals at the interface of the amorphous Al2O3 and ZnO:Al matrix.