Crystalline Si solar cells fabricated by CO2 laser doping
We proposed CO<sub>2</sub> laser doping technique as a fabrication method of c-Si solar cell, and demonstrated its availabilities with the cell characteristics. P and B-doping with relatively high carrier density around 10<sup>20</sup> cm<sup>-3</sup> were realized by the CO<sub>2</sub> laser irradiation. We found that the pulse frequency is one of the most important parameter to improve the cell performances.
22.0% Efficient Laser Doped back Contact Solar Cells
Abstract We present the first laser doped interdigitated back contacted solar cells with efficiency η = 22.0%. The cell area is 2 x 2 cm 2 , and contains the metallization of both busbars. The high flexibility and spatial resolution of our laser doping process enables local n-type and p-type doping with a precision below 30 μm and avoids any masking process.
An analytical approach to the design of electrodes in high-power, fast-transverse-flow CO2 lasers
Abstract Usually, the design of the electrodes of fast-transverse-flow CO 2 lasers relies more on experimental data than on theoretical analysis. Traditional systems sustain a stable, high-power discharge but the current distribution generates a peaked, non-uniform small-signal-gain pattern. We present a theoretical model suitable for the design of electrodes that achieves a quasi uniform gain distribution. The analysis, based on a two-temperature model and the gas-transport equations, computes the electron density that supports a flat gain pattern. Combining the desired electron density with the electron-balance equations, the model determines the required electric field. The results were used to design a new set of electrodes for a home-made fast transverse flow CO 2 laser. A stable, large volume discharge ( 4 × 8 × 90 cm 3 ) with very good uniformity was obtained. The resulting gain distribution was registered in a bi-dimensional map. The peak gain rose from 1.2 m - 1 , attained with the old electrode set, to 1.6 m - 1 with the new one and the gain showed a homogeneous profile.