%0 Journal Article %T Estimation Energy Band Gap of Au/ Nano-Crystal Porous Silicon/Mono-Crystal Silicon Heterojunction %A Hasan A. Hadi %J Open Access Library PrePrints %V 1 %N 1 %P 1-8 %@ 2333-9721 %D 2014 %I Open Access Library %R 10.4236/oalib.preprints.1200044 %X Porous silicon layers were fabricated on p-type crystalline silicon wafers using electrochemical etching ECE process. An investigation of the dependence on applied current density to formed PS layer was made. Porosity of the porous silicon layer and thickness were determined gravimetrically. Increasing the etching current density led to increase the surface porosity and thickness.The porosity varies between 44and 77% for current densities between 25 and 85mA/2.The current density-voltage characteristics of Au/nano-crystal porous silicon/mono-crystal silicon heterojunction was examined under 7.5mW/cm2 power density illuminations. From the experimental data set, the maximum value of responsivity and band-gap energy of porous silicon are deduced to be 1.7A/W and 2.07 eV respectively at45 mA/cm2 etching current density.  %K Porous Silicon %K Electrochemical %K Responsivity %K Heterojunction %K Quantum Confinement %K Energy Gap %U http://www.oalib.com/paper/3098213