At first,we discuss the Structure of the ring Z/(pm ),namely,the structure and amount of nilpotent elements idempotent elements, invertible elements, zero divisors and ideals in Z/ (pm).

Research on the ideality factor of GaN light-emitting diodes on Si substrate;

The ideality factor and the barrier height of Schottky contact on AlGaN/GaN heterostructure are calculated by I-V measurement in a wide temperature range.

An ideality factor of n=3 and a series resistance of RS=93Ω are obtained from the forward current-voltage curve of the device.

Before gate metallization,experiment were made through different surface treatment methods and results show that the Schottky characteristics can be improved,but reverse leakage current and ideal factor can not be obtained fundamentally.

It is found that in the backward voltage segment of the I-V curve the leakage current is larger because of deep-level-assistant tunneling;under little forward voltage metal gathers along with the dislocations thus leads to leakage current;in the generation-recombination and diffusion current segments the restriction from MQWs leads to larger ideal factor;low imp.

After annealing the barrier height and the ideal factor of the diode increased from 0.