Method and Structure for Fabricating Solar Cells Using a Thick Layer Transfer Process

• US 20100178723A1
• Filed: 03/23/2010
• Published: 07/15/2010
• Est. Priority Date: 09/08/2006
• Status: Active Grant

• Current Assignee: Silicon Genesis
• Original Assignee: Silicon Genesis
• Inventors: Henley, Francois J.
• Granted Patent: US 8,110,480 B2
• Time in Patent Office: Days
• US Class Current: 438/71
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond
• CPC Class Codes: H01L 31/03921 including only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 31/068 the potential barriers being only of the PN homojunction type, e.g. bulk silicon PN homojunction solar cells or thin film polycrystalline silicon PN homojunction solar cells
• CPC Class Codes: H01L 31/0687 Multiple junction or tandem solar cells
• CPC Class Codes: H01L 31/1804 comprising only elements of Group IV of the Periodic Table
• 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: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A photovoltaic cell device, e.g., solar cell, solar panel, and method of manufacture. The device has an optically transparent substrate comprises a first surface and a second surface. A first thickness of material (e.g., semiconductor material, single crystal material) having a first surface region and a second surface region is included. In a preferred embodiment, the surface region is overlying the first surface of the optically transparent substrate. The device has an optical coupling material provided between the first surface region of the thickness of material and the first surface of the optically transparent material.

Claims

1-70. -70. (canceled)

71. A method of forming a solar cell, the method comprising:

providing a donor semiconductor substrate having a surface region, a cleave region, and a first thickness of material between the surface region and the cleave region;

performing controlled cleaving by applying thermal energy to detach the first thickness of material from the donor semiconductor substrate;

bonding the first thickness of material to a handle substrate; and

incorporating the first thickness of material bonded to the handle substrate within the solar cell.

72. The method of claim 71 wherein the detached first thickness of material is free standing.

73. The method of claim 72 wherein the detached first thickness of material has a thickness of greater than about 20 um.

74. The method of claim 71 wherein the first thickness of material is bonded to a substrate prior to performing the controlled cleaving.

75. The method of claim 74 wherein the substrate is optically transparent.

76. The method of claim 74 wherein the first thickness of material is bonded to the handle substrate prior to performing the controlled cleaving.

77. The method of claim 74 wherein the first thickness of material is temporarily bonded to a releasable substrate prior to performing the controlled cleaving.

78. The method of claim 77 wherein the releasable substrate comprises a chemically releasable substrate or a thermally releasable substrate.

79. The method of claim 71 further comprising using a plate during the controlled cleaving to confine bending of the detached first thickness of material.

80. The method of claim 79 wherein the plate is transparent to the thermal energy.

81. The method of claim 79 wherein the plate is in contact with, or in close proximity to, the detached first thickness of material.

82. The method of claim 79 wherein the plate comprises a cold plate.

83. The method of claim 79 further comprising causing the plate to act as a carrier of the detached first thickness of material.

84. The method of claim 74 wherein the first thickness of material has a thickness of less than about 50 um.

85. The method of claim 71 wherein the thermal energy is applied from a flashlamp.

86. The method of claim 71 wherein the thermal energy is globally applied to the surface region.

87. The method of claim 71 wherein the thermal energy is locally applied to the surface region.

88. The method of claim 71 wherein the cleave region is defined by implantation of energetic particles into the semiconductor substrate.

89. The method of claim 88 wherein the implantation defines a patterned implant.

90. The method of claim 71 further comprising texturizing the handle substrate or providing the handle substrate with a texture to trap light.

91. The method of claim 71 further comprising coupling the first thickness of material to a contact structure.

92. The method of claim 91 wherein the contact structure is patterned to form a plurality of electrodes, the method further comprising forming a plurality of photovoltaic regions in the first thickness of material, the photovoltaic regions coupled to the plurality of electrodes.

93. The method of claim 91 further comprising coupling the first thickness of material to a second contact structure positioned on an opposite side of the first thickness of material from the contact structure.

94. The method of claim 71 wherein the thermal energy is applied from a thermal sink or source.

95. The method of claim 71 wherein the thermal energy is applied to the donor substrate.

96. The method of claim 71 wherein the thermal energy is applied to the handle substrate attached to the donor substrate.