题目内容
（请给出正确答案）
提问人：网友qq283876581
发布时间：2022-01-06
[主观题]
This article, the second in a series, goes into more __________ technical detail.
简答题官方参考答案
（由简答题聘请的专业题库老师提供的解答）
抱歉！暂无答案，正在努力更新中……
In order to understand and to evaluate evaporated thin films of CdS for their use in electronic devices, a number of diode structures have been extensively studied. These diodes were made rectifying by exploiting the differing properties of metal contacts to the CdS. The metals used behaved as predicted by the classical Schottky theory. Experiments performed under forward bias established that space-charge-limited currents were flowing in the CdS films. These currents indicated a mobility roughly ⅓ to ½ that of single crystal material. Under reverse-bias conditions, Schottky high-field emission was observed. To verify the existence of space-charge-limited currents under forward-bias conditions, the theoretically-predicted inverse-cube dependence for the current as a function of electrode spacing was measured. The square-law currents in the space-charge-limited region implied a free-to-trapped charge ratio of the order of 10 -2 . The position of the Fermi level in the material indicated, however, that this relatively high free-to-trapped-charge-ratio stemmed from compensation of the deep trapping centers. Free-electron mobilities for the films of up to 100 cm 2 /volt sec was measured by observing space-charge-limited currents under pulsed conditions. Values for the mobility were checked by using time-of-flight measurements. These same measurements showed a qualitative agreement with the theory of transient space-charge-limited currents. Under reverse-bias conditions, Schottky-emission observations allowed a calculation of the Richardson factor for the Au-CdS junction that was close to the theoretical value of 120 amps cm -2 deg -2 . Capacitance measurements under reverse bias indicated a true Schottky barrier. These measurements could be used to determine the extent of the penetration of the space-charge region into the CdS film, and thereby to establish the correspondence of the theoretical Schottky-emission field with that measured. 1. The electronic devices studied in this article are () A resistors B capacitors C transistors D diodes 2. The semiconductor studied in this article is () A silicon B germanium C CdS D ZnO 3. The molibities of the carriers in the films are () those in the single crystal material A higher than B lower than C the same as D The above answers are all correct 4. To verify the existence of space-charge-limited currents under forward-bias conditions, () was measured A the theoretically-predicted inverse-cube dependence for the current as a function of electrode spacing B the position of the Fermi level in the material C Free-electron mobilities for the films D Richardson factor for the Au-CdS junction 5. The free-to-trapped charge ratio is () A in the order of 10 -2 B relatively high C stemmed from compensation of the deep trapping centers D The above answers are all correct
