Solar cell and cell mount

A point contact solar device comprising:

• a plurality of laterally spaced apart semiconductive layers each having a top surface and a bottom surface;
• wells of p-conductivity type and n-conductivity type formed in each of said semiconductive layers in an alternating pattern, said wells extending to said bottom surface of each of said semiconductive layers;
• an insulating layer formed on said bottom surface of each of said semiconductive layers and patterned to expose said wells of p-conductivity type and n-conductivity type;
• a conductive layer comprising pairs of conductive regions located beneath and in contact with a bottom surface of each said insulation layer, each pair comprising one positive conductive region and one negative conductive region, said positive conductive region contacting approximately half of the associated insulating layer and said negative conductive region contacting approximately half of said insulating layer;
• said positive conductive region being patterned so as to contact only those of said wells of p-conductivity type located above said positive conductivity region, and said negative conductive region being patterned so as to contact only those of said wells of n-conductivity type located above said negative conductive region;
• a pair of electrically separated bus bar regions located side-by-side beneath said conductive regions, comprising one positive bus bar region and one negative bus bar region;
• said positive bus bar region extending beneath and being electrically separated from each of said negative conductive regions, and said negative bus bar region extending beneath and being electrically separated from each of said positive conductive regions;
• said conductive regions further comprising interleaved fingers with tips, the tips of said fingers of each of said positive conductive regions extending above and being in electrical contact with said positive bus bar region and the tips of said fingers of each of said negative conductive regions extending above and being in electrical contact with said negative bus bar region;
• and
• means for electrically connecting those of said wells not electrically connected to said positive conductive regions to portions of said positive bus bar region located beneath said wells of p conductivity type, and means for electrically connecting those of said wells of n conductivity type not electrically connected to said negative conductive region to portions of said negative bus bar region located beneath said wells of n conductivity type.

A point contact solar device comprising:

• a plurality of solar cell dice, each die comprising:
• a semiconductive layer in which are formed wells of p-conductivity type and n-conductivity type in an alternating pattern, said wells extending to a bottom surface of said semiconductive layer;
• an insulating layer formed on the bottom surface of said semiconductive layer and patterned to expose said wells of p-conductivity type and n-conductivity type;
• a conductive layer patterned to comprise a negative conductive region adjacent to approximately a first half of said insulation layer and in electrical contact with said wells of n-conductivity type in said first half of said die and a positive conductive region adjacent to approximately a second half of said insulation layer and in electrical contact with said wells of p-conductivity type in said second half of said die, said conductive layer further patterned to provide conductive pads in said first half electrically separated from said negative conductive region, and in electrical contact with said second half electrically separated from said positive conductive region, and in electrical contact with said wells of n-conductivity type;
• a plurality of electrically separated bus bars, half of said bus bars being positive bus bars and half being negative bus bars;
• each of said dice having said pads in said first half electrically connected to one of said positive bus bars and having said pads in said second half electrically connected to one of said negative bus bars.

A process for making a point contact solar device comprising:

• forming in and adjacent the bottom surface of a semiconductive layer wells of p-conductivity type and n-conductivity type in an alternating pattern;
• forming an insulation layer on the bottom surface of said semiconductive layer and patterning said insulation layer to provide openings exposing said wells;
• forming conductive layer on said insulation layer;
• patterning said conductive layer to comprise at least two conductive regions, said conductive regions comprising:
• at least one negative conductive region and at least one positive conductive region, said at least one positive conductive region being patterned so as to contact only those wells of p-conductivity type located above said at least one positive conductive region, and said at least one negative conductive region being patterned so as to contact only those of said wells of n-conductivity type located above said at least one negative conductive region, said regions further comprising a plurality of positive contact pads surrounded by said negative conductive region, each of said positive contact pads contacting one or said wells of p-conductivity type located above said at least one negative conductive region, and a plurality of negative contact pads surrounded by said positive conductive region, each of said negative contact pads contacting one of said wells of n-conductivity type located above said at least one positive conductive region;
• forming on said conductive layer a second insulating layer;
• patterning said second insulating layer to expose said contact pads;
• forming a package comprising the steps of:
• forming on a heat spreader device a layer of heat spreader insulating material;
• forming on said layer of heat spreader insulating material a layer of bus bar metal;
• patterning said bus bar metal to comprise a positive bus bar and a negative bus bar separated from each other;
• forming on said bus bars a layer of solder wettable material;
• and
• joining said semiconductive structure and said package with a layer of low temperature solder.

A process for making a point contact solar cell comprising:

• forming in and adjacent to the bottom surface of a semiconductive layer wells of p-conductivity type and n-conductivity type in an alternating pattern;
• forming an insulating layer on the bottom surface of said semiconductive layer and patterning said insulating layer to provide openings exposing said wells;
• forming a conductive layer on said insulating layer;
• patterning said conductive layer to comprise a plurality of conductive regions, said plurality of conductive regions comprising:
• at least one negative conductive region and at least one positive conductive region, said at least one positive conductive region being patterned so as to contact those wells only of p-conductivity type located above said at least one positive conductive region, and said at least one negative conductive region being patterned so as to contact those of said wells only of n-conductivity type located above said at least one negative conductive region;
• and
• a plurality of positive contact pads surrounded by said negative conductive region, each of said positive contact pads contacting one of said wells of p-conductivity type located above said positive contact pad, and a plurality of negative contact pads surrounded by said positive conductive region, each of said negative contact pads contacting one of said wells of n-conductivity type located above said negative contact pad;
• forming on said conductive layer a second insulating layer;
• patterning said second insulating layer to expose said contact pads;
• forming on said second insulating layer and said exposed contact pads a metallization layer;
• and
• patterning said metallization layer to form isolated regions for separately contacting said positive contact pads and said negative contact pads.

A solar cell comprising:

• a semiconductive layer having a top surface, a bottom surface and sides;
• wells of p-conductivity type and n-conductivity type formed in said semiconductive layer in an alternating pattern, said wells extending to said bottom surface of said semiconductive layer;
• a first insulating layer formed on said bottom surface of said semiconductive layer and patterned to expose surfaces of said wells of p-conductivity type and n-conductivity type;
• at least one conductive layer formed beneath said first insulating layer comprising at least one negative conductive region and at least one positive conductive region, said at least one negative conductive region contacting said wells of n-conductivity type and said positive conductive region contacting said wells of p-conductivity type;
• a passivation layer applied to said top surface and said sides of said semiconductive layer;
• wherein said at least one negative conductive region comprises a first perforated conductive layer located beneath one portion of said semiconductive layer and contacting wells of a first conductivity type located in said one portion of said semiconductive layer, and a plurality of first conductive contact pads located beneath the remaining portion of said semiconductive layer and contacting wells of said first conductivity type located in said remaining portion of said semiconductive layer;
• and
• said at least one positive conductive region comprises a second perforated conductive layer located beneath said remaining portion of said semiconductive layer and contacting wells of a second conductivity type located in said remaining portion of said semiconductive layer, and a plurality of second conductive contact pads located beneath said one portion of said semiconductive layer and contacting wells of said second conductivity type located in said one portion of said semiconductive layer;
• said conductive layers being electrically separated from each other and from said contact pads and said conductive layers including fingers interdigitated with each other, said fingers having tips.

A point contact solar device comprising:

• a semiconductive layer in the bottom surface of which are formed wells of p-conductivity type and n-conductivity type in an alternating pattern, the bottom surface of said semiconductive layer being passivated except at locations of said wells;
• a first conductive layer comprising a plurality of first conductive regions beneath and in contact with said bottom surface of said semiconductive layer, said first conductive regions comprising at least one first negative conductive region and at least one first positive conductive region, said first positive and negatve conductive regions being laterally spaced apart and having fingers which interdigitate with fingers of an adjacent first conductive region;
• said at least one first positive conductive region being patterned so as to contact only those of said wells of p-conductivity type located above said first positive conductive region, and to include within it a plurality of negative contact pads in contact with those of said wells of n-conductivity type surrounded by said positive conductive region and said at least one first negative conductive region being patterned so as to contact only those of said wells of n-conductivity type located above said first negative conductive region and to include within it a plurality of positive contact pads in contact with those of said wells of p-conductivity type surrounded by said negative conductive region;
• an insulating layer formed on the bottom surface of said conductive layer and patterned to expose said positive and negative contact pads and to expoe tips of said fingers;
• and
• a second conductive layer formed on the bottom surface of said insulating layer and patterned to form second positive conductive regions adjacent second negative conductive regions,
• said second positive conductive regions being in electrical contact with said wells of p conductivity type in said semiconductive layer not contacted by said first positive conductive regions;
• each of said second positive conductive regions being in electrical contact with tips of said fingers of at least one first positive conductive region adjacent to that first negative conductive region which is above said each second positive conductive region, and
• each of said second negative conductive regions being in electrical contract with tips of said fingers of at least one first negative conductive region adjacent to that first positive region which is above said each second negative conductive region.