Commissariat a L'energie Atomique Et Aux Energies Alternatives

Commissariat a L'energie Atomique

Commissariat a L'energie Atomique Et Aux Alternatives

Sébastien Dubois

Nicolas Enjalbert

Jordi Veirman

Pierre Gidon

Jean-Paul Garandet

Florent Tanay

Pierre Jean Ribeyron

Malek Benmansour

Rémi Monna

Pascal Pochet

Hélène Lignier

Thibaut Desrues

Pierre Bellanger

Charles Seron

Jean-Patrice Rakotoniaina

Tleuzhan Turmagambetov

Miguel Cascant-Lopez

Nicholas Enjalbert

Benoît Martel

Coralie Lorfeuvre

A method for determining the original position of a wafer in an ingot made from semiconductor material comprises the following steps: measuring the interstitial oxygen concentration in an area of the wafer; measuring the concentration of thermal donors formed in said area of the wafer during a previous solidification of the ingot; determining the effective time of a thermal donor formation anneal undergone by the wafer when solidification of the ingot took place, from the thermal donor concentration and the interstitial oxygen concentration; and determining the original position of the wafer in the ingot from the effective time.

Method for locating a wafer in the ingot of same

A method for calibrating a furnace enabling a semiconductor material to be subjected to a first thermal donor formation annealing that includes a temperature rise, a first temperature plateau and a temperature drop of the furnace, the method to including providing a calibration piece of the semiconductor material; determining the interstitial oxygen concentration of the piece; subjecting the piece to a second thermal donor formation annealing in the furnace, the second annealing including rise and drop in temperature of the furnace identical to those of the first annealing and a second plateau at the set temperature for a set time; determining the concentration of thermal donors formed in the piece during the second annealing; determining an equivalent annealing time at the set temperature, corresponding at least to the rise and drop in temperature of the furnace, from the interstitial oxygen concentration, the thermal donor concentration of the piece and the set time.

Method for calibrating an annealing furnace used to form thermal donors

A method for forming a silicon ingot includes the following steps: providing a silicon ingot of variable electrical resistivity and containing interstitial oxygen, determining the interstitial oxygen concentration in different areas of the silicon ingot, calculating the concentration of thermal donors to be created in the different areas to reach a target value of the electrical resistivity, and subjecting the different areas of the silicon ingot to annealing so as to form the thermal donors. The annealing temperature in each area is determined from the thermal donor and interstitial oxygen concentrations of the area and from a predefined annealing time.

Method for forming a doped silicon ingot of uniform resistivity

A restoration device of at least one silicon-based photovoltaic solar cell is provided with a support of the cell and a charge carriers generator configured to generate charge carriers in the photovoltaic solar cell. The device is further provided with a tank designed to be filled by a liquid, and the support is configured to place the photovoltaic solar cell in the liquid.

Device and method for restoring silicon-based photovoltaic solar cells

The restoration device of least one silicon-based photovoltaic solar cell includes a support of the cell, a heat source configured to heat the photovoltaic solar cell, and unit for generating charge carriers in the cell. To better accelerate the restoration kinetics of the solar cell, the device includes an ultrasonic transducer designed to generate ultrasonic waves propagating in the photovoltaic solar cell.

Device and method for restoring silicon-based solar cells using an ultrasound transducer

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 BOcomplexes are thus limited. This applies notably to photovoltaic cells based on monocrystalline or polycrystalline silicon having a high concentration of boron and oxygen.

Method for manufacturing solar cells, attenuating lid phenomena

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.

Determination of the interstitial oxygen concentration in a semiconductor sample

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.

Method for determining interstitial oxygen concentration

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&#xb0; C. and 930&#xb0; C. for a duration of between one and four hours, preferably at a temperature of 900&#xb0; C., give or take 10&#xb0; C., for two hours, give or take 10 minutes.

Method for heat-treating a silicon substrate for the production of photovoltaic cells, and photovoltaic cell production method

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.

Method for mapping oxygen concentration

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&#xb0; C. and 1000&#xb0; C. inclusive for a time of between 1 second and 10 minutes inclusive. The invention is particularly applicable in the photovoltaic cell field.

Method of purifying a crystalline silicon substrate and process for producing a photovoltaic cell

Method for metallization of at least one photovoltaic cell comprising a substrate based on a semiconductor with a first type of conductivity, a layer doped with a second type of conductivity produced in the substrate and forming a front face of the substrate, an antireflection layer produced on the front face of the substrate and forming a front face of the photovoltaic cell. The method comprises at least the steps of:

Method for metallization of photovoltaic cells with multiple annealing operations

Method of processing a substrate containing at least one semiconductor of the SiAtype and comprising at least four separate types of light elements, comprising at least the following steps:

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Scionzier, France

Sébastien Dubois