| 词条 | Transient photocurrent |
| 释义 |
A semiconductor is sandwiched between two extracting electrodes. When it is excited with a short pulse of light (as short as 100 femtoseconds), the photogenerated charges are extracted on the electrodes, resulting in a current, which is detected by an oscilloscope in form of voltage across a resistor. Since the excitation pulse is square, there are two ways to measure TPC: in a “light on” and a “light off” positions. In a “Light on”, the signal is recorded as soon as the excitation pulse is switched on, allowing to observe the build-up of charges on the electrode after the start of excitation. “Light off” measurements show how the charges decay after the pulse is switched off. In contrast to transient photovoltage, TPC measurements are conducted under short circuit condition and yield information about extractable charges, charge recombination and density of states. Quite often, TPC measurements help to build “drift-diffusion” model which reflects trapping and detrapping of the photogenerated charges and the quality of contact between different layers. TPC allows varying different measurement parameters, such as intensity or length of the light pulse, applied voltage, etc. References1. ^{{cite journal|last1=McNeill|first1=Christopher|last2=Inchan|first2=Hwang|last3=Neil|first3=Greenham|title=Photocurrent transients in all-polymer solar cells: Trapping and detrapping effects|journal=Journal of Applied Physics|volume=106|page=024507|doi=10.1063/1.3177337|url=http://scitation.aip.org/content/aip/journal/jap/106/2/10.1063/1.3177337|bibcode = 2009JAP...106b4507M }}
External links
1 : Semiconductor technology |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。