Abstract—In this paper, we demonstrate how the alternating photocurrent influences on the impedance of a device. The GaAsN quantum well (QW) is the good device to achieve this purpose. We first show the QW is sensitive to light and contribute a large photocurrent. And then the QW device receives two signals: a small alternating voltage and a light pulse. The dark current is induced by the applied voltage, and the photocurrent is induced by the light pulse. Both are with the frequency 7 kHz. The two transient currents would convolution to each other. As a result of the convolution, a new alternating current with frequency 0.02 Hz is produced. So the impedance is influenced periodically due to the convoluted current, and the capacitance behaves the sinusoid with frequency 0.02 Hz. We analyze the convolution process, and the experimental data consist with our conclusions. This method is advantageous to the small signals analysis and electrical probing.
Index Terms—GaAsN quantum well, impedance,
photocurrent.
The authors are with the National Chiao Tung University, Hsinchu, Taiwan 30050, and ROC, Taiwan (e-mail: tono.ep98g@nctu.edu.tw, hcp0107@hotmail.com, simonlin7910@hotmail.com, jfchen@cc.nctu.edu.tw).
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Cite: Jia Feng Wang, Chin Pin Huang, Chen Hao Lin, and Jenn-Fang Chen, "The Capacitance Modulated by the Convolution between Optical and Electrical Signals Using the GaAsN/GaAs Quantum Well," International Journal of Engineering and Technology vol. 7, no. 1, pp. 70-74, 2015.
