Discussed is a solar cell including a single crystalline silicon substrate, a polycrystalline silicon layer on a back surface and side surfaces of the single crystalline silicon substrate, a diffusion region on a front surface of the single crystalline silicon substrate, a front passivation layer on the diffusion region, a back passivation layer on the polycrystalline silicon layer, a first electrode connected to the diffusion region through the front passivation layer, and a second electrode connected to the polycrystalline silicon layer through the back passivation layer, wherein the side surfaces of the single crystalline silicon substrate includes a first portion without the polycrystalline silicon layer and a second portion with the polycrystalline silicon layer.

Discussed is a solar cell including a semiconductor substrate, a first tunneling layer entirely formed over a surface of the semiconductor substrate, a first conductive type area disposed on the surface of the semiconductor substrate, and an electrode including a first electrode connected to the first conductive type area.

A preparation method of a low-cost passivated contact full-back electrode solar cell includes: performing alkali polishing on a Si wafer; performing RCA cleaning and HF cleaning; growing a tunnel SiO.sub.x film layer, an in-situ doped amorphous Si film layer, and a texturing mask layer on the back of the Si wafer; performing annealing activation on the amorphous Si film layer to form a polycrystalline Si film layer; etching the texturing mask layer; performing double-sided texturing on the Si wafer; performing HF cleaning to remove the texturing mask layer; depositing an AlO.sub.x film on the front and back of the Si wafer; depositing a SiN.sub.x passivation film on the front and back of the Si wafer; ablating a part of the AlO.sub.x film and a part of the SiN.sub.x passivation film on the back of the Si wafer; and performing screen-printing and sintering on the back of the Si wafer.

Described herein are methods of fabricating solar cells. In an example, a method of fabricating a solar cell includes forming an amorphous dielectric layer on the back surface of a substrate opposite a light-receiving surface of the substrate. The method also includes forming a microcrystalline silicon layer on the amorphous dielectric layer by plasma enhanced chemical vapor deposition (PECVD). The method also includes forming an amorphous silicon layer on the microcrystalline silicon layer by PECVD. The method also includes annealing the microcrystalline silicon layer and the amorphous silicon layer to form a homogeneous polycrystalline silicon layer from the microcrystalline silicon layer and the amorphous silicon layer. The method also includes forming an emitter region from the homogeneous polycrystalline silicon layer.

A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. A trench structure separates the P-type doped region from the N-type doped region. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. The trench structure may include a textured surface for increased solar radiation collection. Among other advantages, the resulting structure increases efficiency by providing isolation between adjacent P-type and N-type doped regions, thereby preventing recombination in a space charge region where the doped regions would have touched.

The present invention relates to a photovoltaic device (10) comprising: a first conducting layer (16), a second conducting layer electrically insulated from the first conducting layer, a porous substrate (20) made of an insulating material arranged between the first and second conducting layers, a light absorbing layer (1) comprising a plurality of grains (2) of a doped semiconducting material disposed on the first conducting layer (16) so that the grains are in electrical and physical contact with the first conducting layer, and a charge conductor (3) made of a charge conducting material partly covering the grains and arranged to penetrate through the first conducting layer (16) and the porous substrate such that a plurality of continuous paths (22) of charge conducting material is formed from the surface of the grains (2) to the second conducting layer (18), wherein the first conducting layer (16) comprises a conducting material, an oxide layer (28) formed on the surface of conducting material, and an insulating coating (29) made of an insulating material deposited on the oxide layer (28) so that the oxide layer and the insulating coating together electrically insulate said paths (22) from the conducting material of the first conducting layer (16).

A method for preparing a P-type crystalline silicon rear electrode, comprising: printing an all-aluminum paste on a P-type crystalline silicon rear passivation layer, then printing a linear interlayer-glass paste on the all-aluminum paste, and finally overprinting rear silver electrodes on the linear middle layer-glass paste. In a solar cell prepared using the method, good contact with silver and aluminum is kept without causing damage to the passivation layer and compromising the conductivity. In the present invention, a complete all-aluminum back surface field can be formed, leading to an improved field passivation property of an electrode region and reduced carrier recombination.

An APD includes a photoconverter and at least one avalanche amplifier of the photocurrent, the amplifier having two layers—a contact layer and a multiplication layer, wherein the multiplication layer is formed on top of the entire conductive wafer, while the contact layer of at least one avalanche amplifier is formed on top of a certain area of the multiplication layer. Meanwhile, outside the contact layer, the multiplication layer functions as a photoconverter. This makes it possible for photocarriers to get into the avalanche amplifier effectively and unimpeded. In order to mitigate the influence of parasite near-surface charge carriers on the avalanche amplifier, its multiplication region is deepened in relation to the upper surface of the photoconverter region. The proposed APD embodiment with less dark current seeping from peripheral areas of the instrument provides higher threshold sensitivity that allows it be on par with state of the art.

A method for manufacturing a solar cell, includes providing a silicon substrate, forming an oxide layer on a first surface of the silicon substrate, forming a doped polycrystalline silicon layer on the oxide layer, forming a passivation layer on the doped polycrystalline silicon layer, printing a metal paste on the passivation layer, and forming a metal contact connected to the doped polycrystalline silicon layer by firing the metal paste to penetrate the passivation layer.

Discussed is a solar cell including a silicon substrate, an emitter area formed on a front surface of the silicon substrate, a tunneling oxide layer formed on a back surface of the silicon substrate, a back surface field area formed on the tunneling oxide layer and formed of a polycrystalline silicon layer, a front passivation film on the emitter area, a front electrode connected to the emitter area by penetrating through the front passivation film, a back passivation film formed on the back surface field area and having an opening and a back electrode connected to the back surface field area via the opening.