Silicon nanoporous pillar array （Si-NPA） is a micron-nanometer hierarchical structure which might be used as functional substrates for constructing optoelectronic nanodevices. This makes understanding the photolumin...Silicon nanoporous pillar array （Si-NPA） is a micron-nanometer hierarchical structure which might be used as functional substrates for constructing optoelectronic nanodevices. This makes understanding the photolumines- cence （PL） from Si-NPA important. We measure the PL of Si-NPA in the range of 11-300K. By analyzing the evolution of the peak energy and intensity with temperature, the ultraviolet, blue, orange and red PL bands from Si-NPA are attributed to the radiative recombination through the deep-levels in silicon oxide, oxygen-related defect states in silicon nanocrystallites （nc-Si）, band-to-band transition within nc-Si, and surface/interface states of nc-Si or between nc-Si and SiOx, respectively. At least two non-radiative recombination processes, which are activated at different temperature ranges, are proposed for the PL intensity variation with temperature. These results might provide strong foundations for designing and constructing optoelectronic devices based on silicon nanostruetures.展开更多
The surface photovoltage(SPV)mechanism of a silicon nanoporous pillar array(Si-NPA)is investigated by using SPV spectroscopy in different external electric fields.Through comparisons with the SPV spectrum of single cr...The surface photovoltage(SPV)mechanism of a silicon nanoporous pillar array(Si-NPA)is investigated by using SPV spectroscopy in different external electric fields.Through comparisons with the SPV spectrum of single crystal silicon(sc-Si),the silicon nano-crystallite(nc-Si)/SiO_(x) nanostructure of Si-NPA is proved to be capable of producing obvious SPV in the wavelength range 300–580 nm.The SPV for the sc-Si layer and the nc-Si/SiO_(x) nanostructure has shown certain contrary characters in different external electric fields.Through analysis,the localized states in the amorphous SiO_(x) matrix are believed to dominate the SPV for the nc-Si/SiO_(x) nanostructure.展开更多
A series of silicon nanoporous pillar array(Si-NPA)samples are prepared with different times of hydrothermal etching,and their surface morphologies are characterized.A systematic study on the evolution trend of the su...A series of silicon nanoporous pillar array(Si-NPA)samples are prepared with different times of hydrothermal etching,and their surface morphologies are characterized.A systematic study on the evolution trend of the surface photovoltage and photoluminescence spectra discloses that the adoption of a prolonged etching time will increase the native degree of oxidation and decrease the interfacial states density localized in the SiO𝑥matrix.These results might be helpful for designing Si-NPA-based semiconductor nanosystems with optimized physical properties.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 61176044 and 11074224.
文摘Silicon nanoporous pillar array （Si-NPA） is a micron-nanometer hierarchical structure which might be used as functional substrates for constructing optoelectronic nanodevices. This makes understanding the photolumines- cence （PL） from Si-NPA important. We measure the PL of Si-NPA in the range of 11-300K. By analyzing the evolution of the peak energy and intensity with temperature, the ultraviolet, blue, orange and red PL bands from Si-NPA are attributed to the radiative recombination through the deep-levels in silicon oxide, oxygen-related defect states in silicon nanocrystallites （nc-Si）, band-to-band transition within nc-Si, and surface/interface states of nc-Si or between nc-Si and SiOx, respectively. At least two non-radiative recombination processes, which are activated at different temperature ranges, are proposed for the PL intensity variation with temperature. These results might provide strong foundations for designing and constructing optoelectronic devices based on silicon nanostruetures.
基金Supported by the National Natural Science Foundation of China under Grant No 11074224.
文摘The surface photovoltage(SPV)mechanism of a silicon nanoporous pillar array(Si-NPA)is investigated by using SPV spectroscopy in different external electric fields.Through comparisons with the SPV spectrum of single crystal silicon(sc-Si),the silicon nano-crystallite(nc-Si)/SiO_(x) nanostructure of Si-NPA is proved to be capable of producing obvious SPV in the wavelength range 300–580 nm.The SPV for the sc-Si layer and the nc-Si/SiO_(x) nanostructure has shown certain contrary characters in different external electric fields.Through analysis,the localized states in the amorphous SiO_(x) matrix are believed to dominate the SPV for the nc-Si/SiO_(x) nanostructure.
基金Supported by the National Natural Science Foundation of China under Grant No 11074224.
文摘A series of silicon nanoporous pillar array(Si-NPA)samples are prepared with different times of hydrothermal etching,and their surface morphologies are characterized.A systematic study on the evolution trend of the surface photovoltage and photoluminescence spectra discloses that the adoption of a prolonged etching time will increase the native degree of oxidation and decrease the interfacial states density localized in the SiO𝑥matrix.These results might be helpful for designing Si-NPA-based semiconductor nanosystems with optimized physical properties.
