Effect of anodization conditions of porous silicon based hydrogen cell parameters

In this thesis, ranging from the state of the micro dimensions to the order of nano-porous silicon and efficient metal (PS) aim to develop cell-based hydrogen. Since the end of 1960?s around the world, the rapid population growth, urbanization, industrialization, heating, electricity consumption and related conditions such as increasing fuel consumption brought about as. Oil prices rise and environmental problems due to limited resources oil and coal to produce electrical energy as an alternative to conventional methods based on the use of renewable resources is gaining importance day by day. Hydrogen energy in renewable energy sources is substantial. Porous silicon hydrogen battery applications, such resources are provided as an example. Porous silicon (PS), crystal structure, voids of nanometer / micrometer-sized silicon surrounded by a network and a large surface area (~ 103 m2cm-3) are characterized by single crystal is a material obtained by silicon electrochemical anodization method. The fabrication of porous silicon (PS) by electrochemical etching is attractive because of the possibility of tuning the pore size, simply by choosing suitable etching conditions and the doping level of the wafer. Porosity of the structure, metal / porous silicon / silicon structures has brought a new perspective on the use of hydrogen as a battery. Metal/PS/Si Schottky-type structures fabricated by metals evaporate on PS/Si structures. Metal / PS / Si Schottky-type contact feature analysis indicates that the electrical angle. In this structure, different concentrations of hydrogen when the self-containing liquids open circuit voltage (Voc) and short-circuit current density (Isc) are. Metal-PS-Si capacitor is similar to a type of structure placed on a liquid hydrogen content. Metal part of the structure of water molecules separating the PS of H + ions accumulate, this accumulation leads to the accumulation of electrons at the Si. Metal and Si 'is taken from a contact potential difference occurs. This is an open circuit voltage (Voc). Open-circuit voltage varies in proportion to the amount of hydrogen exchange environment. Metal-Porous Silicon-Silicon (Metal-PS-Si) structure allows the use of hydrogen as a battery. In the thesis, porous silicon is prepared with different anodization conditions. The different anodization conditions are current density, HF solution, anodization time and intensity of light. Porous silicon is produced by using 15 mA/cm² current density, 1:3 HF solution in dH2O, 8 cm in distance between the light source and the Si to be kept and by changing the anodization time 5-10-25-40-55-70-90-120 minutes produced. SEM analysis of the PS samples were formed under these conditions. The open-circuit voltage and short-circuit current are measured between Au and Si contacts. Under these conditions is the ideal samples showed us open circuit voltage Voc=542mV and short-circuit current Isc = 34.2 µA. The other way of producing porous silicon is by using 15 mA/cm² current, 1:3 HF: dH?O solution, using the anodization time was 55 min at a fixed distance between the light source and the Si 3-6-9-12-15-20-30 cm to be produced by changing. SEM analysis of the PS samples were formed under these conditions, GS. The open-circuit voltage and short-circuit current are measured between Au and Si contacts. Under these conditions, is the ideal samples showed Voc=385mV open circuit voltage and Isc = 20?A short-circuit current. One other way of producing porous silicon is by using 1:3 HF: dH2O solution, using the anodization time ofc 55 min, 8 cm in distance between the light source and Si at a fixed current density of 4, 8, 12, 16, 20, 25, 30, 50 mA / cm² was created by changing. GS structures consisting of SEM samples were analyzed. The open-circuit voltage and short-circuit current are measured between Au and Si contacts. Under these conditions is the ideal sample showed us open circuit voltage Voc = 1170mV and short-circuit current Isc = 11.46 µA. The last way producing the porous silicon is by using anodization time of 55 min, the distance between the light source and the Si 8 cm, the current density 15mA / cm² at a fixed HF: dH?O solution of 1:3, 1:5, 1:7, 1:10, 1:12, 1:15 formed as amended. GS structures consisting of SEM samples were analyzed. The open-circuit voltage and short-circuit current are measured between Au and Si contacts. Under these conditions is the ideal sampe showed us open circuit voltage Voc = 150mV and short-circuit current Isc = 1.32 µA. In these circumstances pore sizes changed and power density of Au-PS-Si hidrogen fuel cell is rised.