Photovoltaic Device and Module with Improved Passivation and a Method of Manufacturing

Abstract

A photovoltaic device, having an improved passivation of surfaces, such as a circumferential outer wall and/or an aperture wall of a back contact metal wrap-through photovoltaic device, for example, into which the pn-junction of first and second semiconductor layers extends. The passivation comprises a passivating layer of a first type, covering at least part of such wall substantially comprised by the depletion region across the pn-junction; a passivating layer of a second type, covering at least part of such wall comprised by the first semiconductor layer, and a passivating layer of a third type covering at least part of the outer wall comprised by the second semiconductor layer.

1 - 30 . (canceled) 
     
     
         31 . A photovoltaic device, comprising:
 a layered structure having a front surface for receiving optical radiation and a rear surface opposite to said front surface, the layered structure having a circumferential outer wall surrounding the layered structure;   at least one electrical contact arrangement positioned at the rear surface, and optionally at the front surface, or at both the front surface and the rear surface;   a first semiconductor layer of a first conductivity type, the first semiconductor layer extending adjacent to the front surface and to the outer wall;   at least one electrical front contact positioned in communication with the front surface and the first semiconductor layer, the at least one electrical front contact being connected to the at least one contact arrangement on the front surface, when the at least one contact arrangement is present on the front surface;   a second semiconductor layer of a second conductivity type, said second layer extending contiguous to the first layer and to the outer wall;   at least one electrical rear contact in communication with the second semiconductor layer and the at least one electrical contact arrangement at the rear surface;   the layered structure optionally comprising at least one aperture defined therein extending from the front surface to the rear surface and being bounded by an aperture wall, the aperture defining an electrical contact path connecting the at least one electrical front contact to the at least one electrical contact arrangement at the rear surface;   the conductivity types of the first semiconductor layer and the second semiconductor layer being of opposite polarity wherein the contact between the first semiconductor layer and the second semiconductor layer is defined by a pn-junction and a depletion region formed across the pn-junction, the pn-junction and depletion region extending to the outer wall, and to the aperture wall, when the at least one defined aperture is present;   a passivating layer of a first type covering the part of the outer wall that is in contact with the pn-junction and depletion region;   a passivating layer of a second type covering the part of the outer wall that is in contact with the first semiconductor layer, the passivating layer of the second type being contiguous to the passivating layer of the first type;   a passivating layer of a third type covering the part of the outer wall that is in contact with the second semiconductor layer, the passivating layer of the third type being contiguous to the passivating layer of the first type; and   when at least one aperture is defined,   the passivating layer of the first type extends into the at least one defined aperture and covers the part of the aperture wall that is in contact with the pn-junction and depletion region; the passivating layer of the second type extends into the at least one defined aperture contiguous to the passivating layer of the first type and covers the part of the aperture wall contacting the first semiconductor layer; and the passivating layer of a third type extends into the at least one defined aperture contiguous to the passivating layer of the first type and covers the part of the aperture wall contacting the second semiconductor layer.   
     
     
         32 . The photovoltaic device according to  claim 31 , wherein the passivating layer of the second type extends over the front surface. 
     
     
         33 . The photovoltaic device according to  claim 32 , wherein the passivating layer of the second type is identical to the passivating layer of the first type. 
     
     
         34 . The photovoltaic device according to  claim 33 , wherein the passivating layers of the first and second type are integral. 
     
     
         35 . The photovoltaic device according to  claim 31 , wherein the passivating layer of the third type extends over the rear surface. 
     
     
         36 . The photovoltaic device according to  claim 35 , wherein the passivating layer of the third type is identical to the passivating layer of the first type. 
     
     
         37 . The photovoltaic device according to  claim 31 , wherein the passivating layers of the first and third type are integral. 
     
     
         38 . The photovoltaic device according to  claim 31 , wherein the passivating layer of the first type has a substantially neutral effective surface charge density. 
     
     
         39 . The photovoltaic device according to  claim 38 , wherein the passivating layer of the first type comprises at least one of amorphous silicon and annealed silicon dioxide. 
     
     
         40 . The photovoltaic device according to  claim 31 , wherein the passivating layer of the second type has an effective surface charge density of a type opposite to and higher than the effective surface charge density of the first semiconductor layer. 
     
     
         41 . The photovoltaic device according to  claim 31 , wherein the passivating layer of the third type has an effective surface charge density of a type opposite to and higher than the effective surface charge density of the second semiconductor layer. 
     
     
         42 . The photovoltaic device according to  claim 31 , wherein the first semiconductor layer is of an n-type conductivity and the passivating layer of the second type comprises at least one of Silicon Nitride, Silicon Dioxide, and wherein the second semiconductor layer is of a p-type conductivity and the passivating layer of the third type comprises at least one of Aluminium Oxide, Titanium Dioxide, Hafnium Oxide. 
     
     
         43 . The photovoltaic device according to  claim 31 , wherein the first semiconductor layer is of a p-type conductivity and the passivating layer of the second type comprises at least one of Aluminium Oxide, Titanium Dioxide, Hafnium Oxide, and wherein the second semiconductor layer is of an n-type conductivity and the passivating layer of the third type comprises at least one of Silicon Nitride, Silicon Dioxide, Silicon Carbide. 
     
     
         44 . The photovoltaic device according to  claim 31  having at least one defined aperture, wherein the passivating layers form an electrical insulating jacket covering the aperture wall of the at least one defined aperture providing an electrical insulation of the layered structure from an electrically conducting electrode arranged in the at least one defined aperture. 
     
     
         45 . The photovoltaic device according to  claim 31 , wherein the layered structure comprises a planar semiconductor body, and wherein each of the first semiconductor layer and the second semiconductor layer are formed by doting of adjacent regions of the semiconductor body. 
     
     
         46 . The photovoltaic device according to  claim 31 , wherein the layered structure comprises a thin-film body, and wherein each of the first semiconductor layer and the second semiconductor layer are applied on the thin-film body. 
     
     
         47 . The photovoltaic device according to  claim 31 , further comprising at least one further covering layer covering at least one of the passivating layers of the first, second and third type. 
     
     
         48 . A method of manufacturing a photovoltaic device, the method comprising the steps of:
 providing a layered structure having a circumferential outer wall, a front surface for receiving optical radiation and a rear surface opposite to the front surface having a circumferential outer wall surrounding the layered structure;   positioning at least one electrical contact arrangement at the rear surface, and optionally at the front surface, or at both the front surface and the rear surface;   extending a first semiconductor layer of a first conductivity type adjacent to the front surface and to the outer wall;   positioning at least one electrical front contact in communication with the front surface and the first semiconductor layer, the at least one electrical front contact being connected to the at least one contact arrangement on the front surface, when the at least one contact arrangement is present on the front surface;   extending a second semiconductor layer of a second conductivity type contiguous to the first semiconductor layer and to the outer wall, the conductivity types of the first semiconductor layer and the second semiconductor layer being of opposite polarity wherein the contact between the first semiconductor layer and the second semiconductor layer defines a pn-junction and a depletion region formed across the pn-junction, the pn-junction and depletion region extending to the outer wall;   placing at least one electrical rear contact in communication with the second semiconductor layer and the at least one electrical contact arrangement at the rear surface;   applying a passivating layer of a first type to cover the part of the outer wall that is in contact with the pn-junction and depletion region;   applying a passivating layer of a second type to cover the part of the outer wall that is in contact with the first semiconductor layer and to be contiguous to the passivating layer of the first type; and   applying a passivating layer of a third type to cover the part of the outer wall that is in contact with the second semiconductor layer and to be contiguous to the passivating layer of the first type.   
     
     
         49 . The method of  claim 48 , including the further steps of
 defining at least one aperture in the layered structure extending from the front surface to the rear surface and being bounded by an aperture wall, the aperture defining an electrical contact path connecting the at least one electrical front contact to the at least one electrical contact arrangement at the rear surface, the contact between the first semiconductor layer and the second semiconductor layer defining the pn-junction and depletion region formed across the pn-junction extending to include the aperture wall of the at least one defined aperture; and   applying a passivating layer of the first type into the at least one defined aperture and covering the part of the aperture wall that is in contact with the pn-junction and depletion region; applying a passivating layer of the second type into the at least one defined aperture contiguous to the passivating layer of the first type and covering the part of the aperture wall contacting the first semiconductor layer; and applying a passivating layer of a third type into the at least one defined aperture contiguous to the passivating layer of the first type and covering the part of the aperture wall contacting the second semiconductor layer.   
     
     
         50 . The method according to  claim 48 , wherein the passivating layer of the first type is applied from either one of the front surface and the rear surface, followed by removal of the passivating layer of the first type from either one of the front and rear surface and from part of the layered structure substantially comprised by the first semiconductor layer and the second semiconductor layer, further applying the passivating layer of the second type from the front surface to be contiguous to the passivating layer of the first type and applying the passivating layer of the third type from the rear surface to be contiguous to the passivating layer of the first type. 
     
     
         51 . The method according to  claim 48 , wherein the passivating layer of the first type is applied from either one of the front surface and the rear surface, followed by removal of the passivating layer of the first type from either one of the front and rear surface and from part of the layered structure substantially comprised by the first semiconductor layer and the second semiconductor layer, further applying the passivating layer of the second type from the front surface, such to be contiguous to the passivating layer of the first type and applying the passivating layer of the third type from the rear surface, such to be contiguous to the passivating layer of the first type, and either one of the passivating layer of the second and/or the third type is removed from either one of the front and rear surface. 
     
     
         52 . The method according to  claim 48 , wherein the photovoltaic device is of a front emitter design, the passivating layer of the first type is applied from either one of the front surface and the rear surface, followed by removal of the passivating layer of the first type from either one of the front and rear surface and from part of the layered structure substantially comprised by the first semiconductor layer and the second semiconductor layer, further applying the passivating layer of the second type from the front surface to be contiguous to the passivating layer of the first type and applying the passivating layer of the third type from the rear surface to be contiguous to the passivating layer of the first type, and the passivating layer of the second type is applied before the passivating layer of the third type. 
     
     
         53 . The method according to  claim 48 , wherein the photovoltaic device is of a rear emitter design, the passivating layer of the first type is applied from either one of the front surface and the rear surface, followed by removal of the passivating layer of the first type from either one of the front and rear surface and from part of the layered structure substantially comprised by the first semiconductor layer and the second semiconductor layer, further applying the passivating layer of the second type from the front surface to be contiguous to the passivating layer of the first type and applying the passivating layer of the third type from the rear surface to be contiguous to the passivating layer of the first type, and the passivating layer of the third type is applied before the passivating layer of the second type. 
     
     
         54 . The method according to  claim 48 , wherein the passivating layers of the first and second type are integral, and the integral passivating layer is applied from the front surface after which the passivating layer of the third type is applied from the rear surface. 
     
     
         55 . The method according to  claim 48 , wherein the passivating layers of the first and third type are integral, and the integral passivating layer is applied from the rear surface after which the passivating layer of the second type is applied from the front surface. 
     
     
         56 . A plurality of photovoltaic devices according to  claim 31  arranged in stacked operative relationship with one another to form a multi junction photovoltaic device. 
     
     
         57 . A plurality of photovoltaic devices according to  claim 31  arranged in operative electrical connection to one another to form a photovoltaic module.