Photovoltaic device

• US 5,738,731 A
• Filed: 08/31/1994
• Issued: 04/14/1998
• Est. Priority Date: 11/19/1993
• Status: Expired due to Term

• Current Assignee: Crystal Device Corporation, Megachips Corporation
• Original Assignee: Crystal Device Corporation, Megachips Corporation
• Inventors: Hikawa, Tetsuo, Takata, Akira, Sawada, Takashi, Shindo, Masahiro, Kosaka, Daisuke, Asakawa, Toshifumi, Ukai, Yukihiro
• Primary Examiner(s): Weisstuch, Aaron
• Application Number:
  US08/298,800
• Time in Patent Office: 1,322 Days
• Field of Search: 136/249 TJ, 136/252, 136/260-262, 136/264-265, 257/184, 257/440, 257/461
• US Class Current: 136/249
• CPC Class Codes: B81B 2203/0109 Bridges
• CPC Class Codes: B81B 2203/0118 Cantilevers
• CPC Class Codes: B81B 2203/0127 Diaphragms, i.e. structures separating two media that can control the passage from one medium to another; Membranes, i.e. diaphragms with filtering function
• CPC Class Codes: B81B 5/00 Devices comprising elements which are movable in relation to each other, e.g. comprising slidable or rotatable elements
• CPC Class Codes: B81C 1/0038 Processes for creating layers of materials not provided for in groups B81C1/00357 - B81C1/00373
• CPC Class Codes: B81C 2201/0109 Sacrificial layers not provided for in B81C2201/0107 - B81C2201/0108
• CPC Class Codes: C23C 16/48 by irradiation, e.g. photolysis, radiolysis, particle radiation
• CPC Class Codes: C23C 16/486 using ion beam radiation
• CPC Class Codes: C23C 16/511 using microwave discharges
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G02F 1/136281 having a transmissive semiconductor substrate
• CPC Class Codes: H01H 59/0009 making use of micromechanics
• CPC Class Codes: H01J 37/32678 Electron cyclotron resonance
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/1203 the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688
• CPC Class Codes: H01L 31/03762 including only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 31/0693 the devices including, apart from doping material or other impurities, only AIIIBV compounds, e.g. GaAs or InP solar cells
• CPC Class Codes: H01L 31/0725 Multiple junction or tandem solar cells
• CPC Class Codes: H01L 31/073 : comprising only AIIBVI compound semiconductors, e.g. CdS/CdTe solar cells
• CPC Class Codes: H01L 31/078 : including different types of potential barriers provided for in two or more of groups H01L31/062 - H01L31/075
• CPC Class Codes: H01L 31/1804 : comprising only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 31/1828 : the active layers comprising only AIIBVI compounds, e.g. CdS, ZnS, CdTe
• CPC Class Codes: H01L 31/186 : Particular post-treatment for the devices, e.g. annealing, impurity gettering, short-circuit elimination, recrystallisation
• CPC Class Codes: H02N 1/002 : Electrostatic motors
• CPC Class Codes: Y02E 10/543 : Solar cells from Group II-VI materials
• CPC Class Codes: Y02E 10/544 : Solar cells from Group III-V materials
• CPC Class Codes: Y02E 10/547 : Monocrystalline silicon PV cells
• CPC Class Codes: Y02E 10/548 : Amorphous silicon PV cells
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

A solar cell comprising:

a first junction part having a first conductivity type first semiconductor film and a second conductivity type second semiconductor film formed on an upper surface of said first semiconductor film; and

a second junction part having a first conductivity type third semiconductor film formed on an upper surface of said second semiconductor film and a second conductivity type fourth semiconductor formed on an upper surface of said third semiconductor film,

said junction parts arranged from that having a larger forbidden band width along the direction of progress of light through said semiconductor layers,

said first, second, third, and fourth semiconductor films being formed of single-crystalline filming;

wherein an interlayer conductor prepared from a metal forming ohmic junctions with each of said junction parts and having a thickness capable of transmitting light therethrough is interposed between said first and second junction parts; and

wherein said second semiconductor film arranged on one side of said interlayer conductor is different in crystal orientation from said third semiconductor film arranged on the other side of said interlayer conductor.

Claims

1. A solar cell comprising:

a first junction part having a first conductivity type first semiconductor film and a second conductivity type second semiconductor film being formed on an upper surface of said first semiconductor film; and

a second junction part having a first conductivity type third semiconductor film being formed on an upper surface of said second semiconductor film and a second conductivity type fourth semiconductor film being formed on an upper surface of said third semiconductor film,

said junction parts being arranged from that having a larger forbidden bandwidth along a direction of progress of light,

said first, second, third and fourth semiconductor films being formed by single-crystalline films;

wherein an interlayer conductor prepared from a metal having an ohmic junction property with respect to said junction parts and having a thickness capable of transmitting light is interposed between said first and second junction parts; and

wherein said second semiconductor film being arranged on one side of said interlayer conductor is different in crystal orientation from said third semiconductor film being arranged on another side of said interlayer conductor.

2. A solar cell in accordance with claim 1, further comprising:

a substrate;

a first electrode being connected to said first semiconductor film and being formed on an upper surface of said substrate; and

a second electrode being connected to said fourth semiconductor film.

3. A solar cell in accordance with claim 1, wherein each said single-crystalline film is formed by supplying reaction gases at a low temperature below a crystalline temperature and simultaneously applying beams from a plurality of directions being perpendicular to densest crystal planes of a plurality of different directions of single-crystalline film to be formed.

4. A solar cell in accordance with claim 1, wherein each said single-crystalline film is formed by applying beams from a plurality of directions being perpendicular to densest crystal planes of a plurality of different directions of single-crystalline film to be formed at a low temperature below a crystallization temperature of a previously formed amorphous or polycrystalline thin film.

5. A solar cell in accordance with claim 1, wherein each said single-crystalline film is prepared from a group II-VI compound.

6. A solar cell in accordance with claim 1, wherein each said single-crystalline film is prepared from a group III-V compound.