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A novel asymmetrical GaAs/AlGaAs photoconductance infrared detector based on the new idea proposed in this paper has been developed,which uses the intersubband transition within the same conduction (valence) band due to infrared radiation.The detectors with two wells or six wells grown by Metalorganic Chemical Vapor Deposition (MOCVD) system are fabricated by etching a mesa size of 200μm×200μm.Evident infrared absorption on the wavelength from 5 to 10μm has been observed for two samples,so has the peak of negative differential conductance.It is demonstrated that the photocurrent together with the signal|to|noise ratio increases with the number of the wells,but have nothing to do with the increase of the noise current under the same electric field,i.e.,the voltage drops per period,as is different from the conventional GaAs/AlGaAs Quantum Well Infrared Photodetectors (QWIPs).The noise current is one order’s magnitude lower than that of the conventional GaAs/AlGaAs QWIPs.It is anticipated that the photocurrent and detector performances can be improved further by increasing the number of wells and optimizing the structural parameters.
A novel asymmetrical GaAs / AlGaAs photoconductance infrared detector based on the new idea proposed in this paper has been developed, which uses the intersubband transition within the same conduction (valence) band due to infrared radiation. Detectors with two wells or six wells grown by Metalorganic Chemical Vapor Deposition (MOCVD) system are fabricated by etching a mesa size of 200 μm × 200 μm. Evident infrared absorption on the wavelength from 5 to 10 μm has been observed for two samples, so has the peak of negative differential conductance. It is said that the photocurrent together with the signal | to | noise ratio increases with the number of the wells, but have nothing to do with the increase of the noise current under the same electric field, ie, the voltage drops per period, as is different from the conventional GaAs / AlGaAs Quantum Well Infrared Photodetectors (QWIPs). The noise current is one order’s magnitude lower than that of the conventional GaAs / AlGaAs QWIPs.It is ant icipated that the photocurrent and detector performances can be improved further by increasing the number of wells and optimizing the structural parameters.