描述
半导体表面对环境气氛和接触材料很敏感。表面层对外来电荷(正的或负的电荷)的吸附引起表面能带的弯曲(向上或向下),剧烈地影响半导体中光电子发射的特性。图3中的E表示表面能带向下弯曲的势能,实际有效电子亲和势xeff=x-E。如果E>x,则xeff就成为负值。负电子亲和势(NEA)材料(如GaAs、InGaAsP与Cs2O的接触)的光电子发射的量子产额相当可观,是发展半导体光阴极的重要基础。
HP/Agilent 4934A/001/021 TIMS Transmission Impairment
HP/Agilent E4440-60201 Board Assembly Reference
HP/Agilent E4440-60195 Printed circuit assembly
HP Agilent 8657D Pi4 Dqpsk Mod Signal Generator
HP Agilent 8901B/001/H09 Modulation Analyzer Refurbish
HP Agilent Digital Multimeter Series HP E1412A
HP/Agilent 16741A Timing and State Module. 4M memory, 2
HP/Agilent 16750A Logic Analyzer Module
HP/Agilent 81522A Optical Head 1000-1650nm
Agilent HP 42843A Bias Current Cable for 42842B &42841A
HP/Agilent 70905A RF Section, 50 kHz to 22 GHz
HP – AGILENT 5350B 40GHz MICOWAVE COUNTER W/OPT! 5352B
@@@ CALIBRATED @@@ CALBRATED @@@ CALIBRATED @@@
AGILENT / HP 84904L 11 dB ATTENUATOR 24V DRIVE DC 40GHz
AGILENT/HP 84904K 11 dB ATTENUATOR 24V DRIVE DC 26.5GHz
Agilent HP 8157A/012 Optical Attenuator