Patent application number | Description | Published |
20100041175 | METHOD OF PURIFYING A CRYSTALLINE SILICON SUBSTRATE AND PROCESS FOR PRODUCING A PHOTOVOLTAIC CELL - The invention relates to a method of purifying a crystalline silicon substrate and to a process for producing a photovoltaic cell. The method of purifying a crystalline silicon substrate according to the invention is of the type that includes a step of extracting impurities by external gettering and which includes, before said step of extracting the impurities by external gettering, at least one step of rapidly annealing the substrate at a temperature of between 750° C. and 1000° C. inclusive for a time of between 1 second and 10 minutes inclusive. The invention is particularly applicable in the photovoltaic cell field. | 02-18-2010 |
20120329194 | METHOD FOR TREATING A SILICON SUBSTRATE FOR THE PRODUCTION OF PHOTOVOLTAIC CELLS, AND PHOTOVOLTAIC CELL PRODUCTION METHOD - The invention relates to a method for treating a silicon substrate for the production of photovoltaic cells against reduction in yield during the illumination of said photovoltaic cells. The invention also relates to a method for producing photovoltaic cells from the treated substrate. To said end, the invention relates to a method for treating a silicon substrate for the production of photovoltaic cells, said method including the following steps: a) providing a silicon substrate obtained from a metallurgically purified load, and b) annealing said substrate by heating the substrate to a temperature between 880° C. and 930° C. for a duration of between one and four hours, preferably at a temperature of 900° C., give or take 10° C., for two hours, give or take 10 minutes. | 12-27-2012 |
20130158889 | METHOD FOR MAPPING OXYGEN CONCENTRATION - A method for determining the oxygen concentration of a sample made of a semiconductor material includes a heat treatment step of the sample to form thermal donors, the measurement of the resistivity in an area of the sample, the determination of the thermal donor concentration from a relation expressing the charge carrier mobility according to an ionized dopant impurity concentration, by adding to the dopant impurity concentration four times the thermal donor concentration, and from the measured resistivity value. The method finally includes determining the oxygen concentration from the thermal donor concentration. | 06-20-2013 |
20140033797 | METHOD FOR DETERMINING INTERSTITIAL OXYGEN CONCENTRATION - A method for determining the interstitial oxygen concentration of a sample made from a p-doped semiconductor material includes a step of heat treatment of the sample in order to form thermal donors, determining the duration of the heat treatment required to obtain a compensated semiconductor material, determining the thermal donors concentration in the sample of compensated semiconductor material, from the charge carriers concentration, and determining the oxygen concentration from the thermal donors of and the duration of the heat treatment. | 02-06-2014 |
20140147956 | METHOD FOR MANUFACTURING SOLAR CELLS, ATTENUATING LID PHENOMENA - To reduce degradation, by the LID effect, of the conversion efficiency of photovoltaic cells made of crystalline silicon, one or more steps of controlled introduction of voids into the silicon are carried out by one or more steps chosen from among: siliciding, nitriding, ion implantation, laser irradiation, mechanical bending stress applied on one face of the silicon substrate, in combination with a temperature promoting the formation of voids in the substrate. These voids make it possible to reduce the level of interstitial oxygen by an effect of diffusion of VO complexes and precipitation of oxygen. The introduction of voids has the other effect of reducing the level of autointerstitials, and therefore of limiting the formation of interstitial boron. The phenomena of LID by activation of B | 05-29-2014 |
20140163913 | DETERMINING THE DOPANT CONTENT OF A COMPENSATED SILICON SAMPLE - The method for determining the concentrations of dopant impurities in a silicon sample includes provision of a silicon ingot including donor-type dopant impurities and acceptor-type dopant impurities, a step for determining the position of a first area of the ingot in which a transition takes place between a first conductivity type and a second opposite conductivity type, a step for measuring the concentration of free charge carriers in the second area of the ingot, distinct from the first area, by Hall effect, Fourier transform infrared spectroscopy or a method using the lifetime of the charge carriers, and a step for determining the concentrations of dopant impurities in the sample from the position of the first area and the concentration of free charge carriers in the second area of the ingot. | 06-12-2014 |
20140167731 | DETERMINING THE DOPANT CONTENT OF A COMPENSATED SILICON SAMPLE - Method for determining dopant impurities concentrations in a silicon sample involves provision of a silicon ingot including donor type dopant impurities and acceptor type dopant impurities, a step for determining the position of a first area of the ingot in which a transition takes place between a first conductivity and a second opposite conductivity types, by subjecting ingot portions to chemical treatment based on hydrofluoric acid, nitric acid and acetic acid, enabling defects to be revealed on one of the portions corresponding to the transition between the first conductivity and the second conductivity types, a step of measuring the concentration of free charge carriers in a second area of the ingot, different from the first area, and a step for determining concentrations of dopant impurities in the sample from the position of the first area and the concentration of free charge carriers in the second area of the ingot. | 06-19-2014 |
20150055677 | DETERMINATION OF THE INTERSTITIAL OXYGEN CONCENTRATION IN A SEMICONDUCTOR SAMPLE - A method for determining the oxygen concentration of a sample made from p-type semiconductor material includes a thermal treatment step to form the thermal donors, a measuring step of the charge carrier concentration of the sample at a temperature between 0 K and 100 K, a step of determining the thermal donor concentration of the sample from the charge carrier concentration and the temperature of the sample, and a step of determining the interstitial oxygen concentration from the thermal donor concentration. | 02-26-2015 |