Gallium nitride(GaN)/porous silicon(PSi)film was prepared using a pulsed laser deposition method and 1064 nm Nd:YAG laser for optoelectronic applications and a series of Psi substrates were fabricated using a photoele...
详细信息
Gallium nitride(GaN)/porous silicon(PSi)film was prepared using a pulsed laser deposition method and 1064 nm Nd:YAG laser for optoelectronic applications and a series of Psi substrates were fabricated using a photoelectrochemical etching method assisted by laser at different etching times for 2.5–15 min at 2.5 min intervals.X-ray diffraction,room-temperature photoluminescence,atomic force microscopy and field emission scanning electron microscopy images,and electrical characteristics in the prepared GaN on the Psi film were *** optimum Psi substrate was obtained under the following conditions:10 min,10 mA/cm^(2),and 24%hydrofluoric *** substrate exhibited two highly cubic crystalline structures at(200)and(400)orientations and yellow visible band photoluminescence,and homogeneous pores formed over the entire *** pores had steep oval shapes and were accompanied by small dark pores that appeared topographically and *** GaN/Psi film fabricated through PLD exhibited a high and hexagonal crystallographic texture in the(002)*** properties results revealed that the photoluminescence emission of the deposited nano-GaN films was in the ultraviolet band(374 nm)related to GaN material and in the near-infrared band(730 nm)related to the Psi *** topographical and morphological results of the GaN films confirmed that the deposited film contained spherical grains with an average diameter of 51.8 nm and surface roughness of 4.8 *** GaN/Psi surface showed a cauliflower-like morphology,and the built-in voltage decreased from 3.4 to 2.7 eV after *** fabricated GaN/Psi film exhibited good electrical characteristics.
Background:National forest inventory and forest monitoring systems are more important than ever considering continued global degradation of trees and *** systems are especially important in a country like Bangladesh,w...
详细信息
Background:National forest inventory and forest monitoring systems are more important than ever considering continued global degradation of trees and *** systems are especially important in a country like Bangladesh,which is characterised by a large population density,climate change vulnerability and dependence on natural *** the aim of supporting the Government’s actions towards sustainable forest management through reliable information,the Bangladesh Forest Inventory(BFI)was designed and implemented through three components:biophysical inventory,socio-economic survey and remote sensing-based land cover *** article documents the approach undertaken by the Forest Department under the Ministry of Environment,Forests and Climate Change to establish the BFI as a multipurpose,efficient,accurate and replicable national forest *** design,operationalization and some key results of the process are ***:The BFI takes advantage of the latest and most well-accepted technological and methodological ***,it was designed through a collaborative process which drew from the experience and knowledge of multiple national and international ***,1781 field plots were visited,6400 households were surveyed,and a national land cover map for the year 2015 was *** technological enhancements include a semi-automated segmentation approach for developing the wall-to-wall land cover map,an object-based national land characterisation system,consistent estimates between sample-based and mapped land cover areas,use of mobile apps for tree species identification and data collection,and use of differential global positioning system for referencing plot ***:Seven criteria,and multiple associated indicators,were developed for monitoring progress towards sustainable forest management goals,informing management decisions,and national and international reporting needs.A wide range of biophysica
暂无评论