本文介绍了一种基于NiosII的指纹识别SOPC(System On Programmable Chip)设计方案。NiosII软核处理器的最大特点是其可配置性。设计者不必局限于一般的处理器技术(比如ARM、DSP),而是根据自己的需求定制专门的处理器完成系统设计。本文...本文介绍了一种基于NiosII的指纹识别SOPC(System On Programmable Chip)设计方案。NiosII软核处理器的最大特点是其可配置性。设计者不必局限于一般的处理器技术(比如ARM、DSP),而是根据自己的需求定制专门的处理器完成系统设计。本文不仅具体说明了指纹识别系统的基本原理,硬件结构,软件设计基本过程,还对系统的软件与硬件进行了优化,结果使系统速度相对于最初整体提升了近30%。展开更多
In recent years,copper iodide(CuI)is an emerging p-type wide bandgap semiconductor with high intrinsic Hall mobility,high optical absorption and large exciton binding energy.However,the spectral response and the photo...In recent years,copper iodide(CuI)is an emerging p-type wide bandgap semiconductor with high intrinsic Hall mobility,high optical absorption and large exciton binding energy.However,the spectral response and the photoelectric conversion efficiency are limited for CuI-based heterostructure devices,which is related to the difficulty in fabrication of high-quality CuI thin films on other semiconductors.In this study,a p-CuI/n-Si photodiode has been fabricated through a facile solid-phase iodination method.Although the CuI thin film is polycrystalline with obvious structural defects,the CuI/Si diode shows a high weak-light sensitivity and a high rectification ratio of 7.6×10^(4),indicating a good defect tolerance.This is because of the unilateral heterojunction behavior of the formation of the p^(+)n diode.In this work,the mechanism of photocurrent of the p^(+)n diode has been studied comprehensively.Different monochromatic lasers with wavelengths of 400,505,635 and 780 nm have been selected for testing the photoresponse.Under zero-bias voltage,the device is a unilateral heterojunction,and only visible light can be absorbed at the Si side.On the other hand,when a bias voltage of-3 V is applied,the photodiode is switched to a broader“UV-visible”band response mode.Therefore,the detection wavelength range can be switched between the“Visible”and“UV-visible”bands by adjusting the bias voltage.Moreover,the obtained CuI/Si diode was very sensitive to weak light illumination.A very high detectivity of 10^(13)-1014 Jones can be achieved with a power density as low as 0.5μW/cm^(2),which is significantly higher than that of other Cu-based diodes.These findings underscore the high application potential of CuI when integrated with the traditional Si industry.展开更多
文摘本文介绍了一种基于NiosII的指纹识别SOPC(System On Programmable Chip)设计方案。NiosII软核处理器的最大特点是其可配置性。设计者不必局限于一般的处理器技术(比如ARM、DSP),而是根据自己的需求定制专门的处理器完成系统设计。本文不仅具体说明了指纹识别系统的基本原理,硬件结构,软件设计基本过程,还对系统的软件与硬件进行了优化,结果使系统速度相对于最初整体提升了近30%。
基金National Natural Science Foundation of China(62074056)Fundamental Research Funds for the Central Universities。
文摘In recent years,copper iodide(CuI)is an emerging p-type wide bandgap semiconductor with high intrinsic Hall mobility,high optical absorption and large exciton binding energy.However,the spectral response and the photoelectric conversion efficiency are limited for CuI-based heterostructure devices,which is related to the difficulty in fabrication of high-quality CuI thin films on other semiconductors.In this study,a p-CuI/n-Si photodiode has been fabricated through a facile solid-phase iodination method.Although the CuI thin film is polycrystalline with obvious structural defects,the CuI/Si diode shows a high weak-light sensitivity and a high rectification ratio of 7.6×10^(4),indicating a good defect tolerance.This is because of the unilateral heterojunction behavior of the formation of the p^(+)n diode.In this work,the mechanism of photocurrent of the p^(+)n diode has been studied comprehensively.Different monochromatic lasers with wavelengths of 400,505,635 and 780 nm have been selected for testing the photoresponse.Under zero-bias voltage,the device is a unilateral heterojunction,and only visible light can be absorbed at the Si side.On the other hand,when a bias voltage of-3 V is applied,the photodiode is switched to a broader“UV-visible”band response mode.Therefore,the detection wavelength range can be switched between the“Visible”and“UV-visible”bands by adjusting the bias voltage.Moreover,the obtained CuI/Si diode was very sensitive to weak light illumination.A very high detectivity of 10^(13)-1014 Jones can be achieved with a power density as low as 0.5μW/cm^(2),which is significantly higher than that of other Cu-based diodes.These findings underscore the high application potential of CuI when integrated with the traditional Si industry.
