Abstract: A method for recovering C2 components in a methane-containing industrial gas includes the steps of (1) cooling a compressed methane-containing industrial gas and performing gas-liquid separation; (2) absorbing C2 components in the gas phase by using an absorbent to obtain an absorption rich liquid; (3) returning the absorption rich liquid to the compression in step (1) or mixing the absorption rich liquid with the liquid phase obtained in step (1) to obtain a mixed liquid, and depressurizing the mixed liquid or the absorption rich liquid; (4) performing methane desorption on the depressurized stream to obtain a rich absorbent, or performing second gas-liquid separation on the depressurized stream, followed by methane desorption on the second liquid phase to obtain a rich absorbent; and (5) desorbing and separating the rich absorbent to obtain a lean absorbent and an enriched gas, and recycling and reusing the lean absorbent.

Abstract: Provided are a solar cell sheet and a heat treatment process thereof. The heat treatment process includes: a) sifting from solar cell sheets after printed and sintered cell sheets with conversion efficiency lower than 18% and filling factor thereof higher than 70%; b) performing low temperature annealing on the sifted cell sheets; c) sifting from the cell sheets after low temperature annealing cell sheets with lowered filling factor; d) re-sintering the sifted cell sheets; and e) sifting from the re-sintered cell sheets cell sheets with conversion efficiency lower than 18% and returning back to b) until most or all of the sifted meet demands.

Abstract: Provided are a solar cell sheet and a heat treatment process thereof The heat treatment process includes: a) sifting from solar cell sheets after printed and sintered cell sheets with conversion efficiency lower than 18% and filling factor thereof higher than 70%; h) performing low temperature annealing on the sifted cell sheets; c) sifting from the cell sheets after low temperature annealing cell sheets with lowered filling factor; d) re-sintering the sifted cell sheets; and e) sifting from the re-sintered cell sheets cell sheets with conversion efficiency lower than 18% and returning back to b) until most or all of the sifted meet demands.

Abstract: A method for manufacturing a solar cell from a semiconductor substrate (1) of a first conductivity type, the semiconductor substrate having a front surface (2) and a back surface (3). The method includes in a sequence: texturing (102) the front surface to create a textured front surface (2a); creating (103) by diffusion of a dopant of the first conductivity type a first conductivity-type doped layer (2c) in the textured front surface and a back surface field layer (4) of the first conductivity type in the back surface; removing (105; 104a) the first conductivity-type doped layer from the textured front surface by an etching process adapted for retaining texture of the textured front surface; creating (106) a layer of a second conductivity type (6) on the textured front surface by diffusion of a dopant of the second conductivity type into the textured front surface.

Abstract: A method for manufacturing a solar cell from a semiconductor substrate (1) of a first conductivity type, the semiconductor substrate having a front surface (2) and a back surface (3). The method includes in a sequence: texturing (102) the front surface to create a textured front surface (2a); creating (103) by diffusion of a dopant of the first conductivity type a first conductivity-type doped layer (2c) in the textured front surface and a back surface field layer (4) of the first conductivity type in the back surface; removing (105; 104a) the first conductivity-type doped layer from the textured front surface by an etching process adapted for retaining texture of the textured front surface; creating (106) a layer of a second conductivity type (6) on the textured front surface by diffusion of a dopant of the second conductivity type into the textured front surface.