# US 2009/0260673 A1 · Preventing Harmful Polarization Of Solar Cells > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2009/0260673 A1 - Document ID: US20090260673A1 - Status: Published application - Kind: A1 - Application number: 12/477,796 - Filed: 2009-06-03 - Published: 2009-10-22 - Earliest claimed: 2005-03-03 - Assignees: SunPower Corporation - Inventors: Richard M. Swanson; Denis De Ceuster; Vikas Desai; Douglas H. Rose; David D. Smith; Neil Kaminar - Web page: https://patentgrep.com/patent/US20090260673A1 ## CPC - H10F 77/311: {for photovoltaic cells} - H02J 3/38: Arrangements for feeding a single network from two or more generators or sources in parallel; Arrangements for feeding already energised networks from additional generators or sources in parallel - H02S 30/10: Frame structures - H02S 40/32: comprising DC/AC inverter means associated with the PV module itself, e.g. AC modules - H02S 40/36: characterised by special electrical interconnection means between two or more PV modules, e.g. electrical module-to-module connection - H10F 19/80: Encapsulations or containers for integrated devices, or assemblies of multiple devices, having photovoltaic cells - H10F 19/85: Protective back sheets - H10F 19/902: {for series or parallel connection of photovoltaic cells} - H10F 19/908: {for back-contact photovoltaic cells} - H10F 77/244: {made of transparent conductive layers, e.g. transparent conductive oxide [TCO] layers} - H10F 77/315: {the coatings being antireflective or having enhancing optical properties} - Y02B 10/10: Photovoltaic [PV] - Y02E 10/50: Photovoltaic [PV] energy - Y02E 10/52: PV systems with concentrators - Y02E 10/547: Monocrystalline silicon PV cells - Y02E 10/56: Power conversion systems, e.g. maximum power point trackers - Y10T 29/49117: Conductor or circuit manufacturing - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H02S: GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES (obtaining electrical energy from radioactive sources G21H1/12; light sensitive inorganic semiconductor devices H10F; light sensitive organic semiconductor devices H10K30/00; thermoelectric devices H10N10/00; pyroelectric devices H10N15/00) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract In one embodiment, harmful solar cell polarization is prevented or minimized by providing a conductive path that bleeds charge from a front side of a solar cell to the bulk of a wafer. The conductive path may include patterned holes in a dielectric passivation layer, a conductive anti-reflective coating, or layers of conductive material formed on the top or bottom surface of an anti-reflective coating, for example. Harmful solar cell polarization may also be prevented by biasing a region of a solar cell module on the front side of the solar cell. ## Claims ### Claim 1 A method of preventing harmful polarization of solar cells, the method comprising: connecting a plurality of solar cells in series, the series having a positive terminal at one end and a negative terminal at an opposing end, the positive terminal being at positive potential relative to the negative terminal, each solar cell in the plurality of solar cells having an N-type front side diffusion region and a dielectric over the N-type front side diffusion region; grounding a frame of the plurality of solar cells; grounding the positive terminal; and coupling the plurality of solar cells to an inverter configured to convert direct current generated by the plurality of solar cells to alternating current to be provided to a power grid. ### Claim 2 (depends on 1) The method of claim 1 wherein the plurality of solar cells comprise backside contact solar cells. ### Claim 3 (depends on 1) The method of claim 1 further comprising: unbalancing a balanced output provided by the plurality cells to the inverter. ### Claim 4 A solar energy system comprising: a solar cell module array comprising a plurality of backside contact solar cells, the solar cells being coupled in series such that a first node of the series is at a positive potential and a second opposing node of the series is at a negative potential relative to the first node, each solar cell in the plurality of backside contact solar cells having a doped front side diffusion region and a dielectric over the doped front side diffusion region; a frame of a solar cell module in the solar cell module array; an inverter configured to convert direct current generated by the solar cell module array to alternating current to be provided to a power grid; wherein the first node of the series and the frame are grounded to reduce positive potential between the solar cells and the frame. ### Claim 5 (depends on 4) The solar energy system of claim 4 wherein the inverter is configured to receive a balanced voltage from the solar cell module array and further comprising: a resistor coupling the first node of the series to ground, the resistor having a value configured to unbalance the balanced voltage from the solar cell module array. ### Claim 6 A solar energy system comprising: a series of backside contact solar cells in a solar cell module array, the series of backside contact solar cells having a first node and a second node opposite the first node, the first node being at a positive potential and the second node being at a negative potential relative to the first node, each solar cell in the series of backside contact solar cells having a front side facing the sun during normal operation and a backside opposite the front side; a frame of a solar cell module in the solar cell module array, the frame being tied to ground; an inverter configured to convert direct current generated by the solar cell module array to alternating current to be provided to a power grid; wherein either the first node or the second node is tied to ground, the first node being tied to ground when solar cells in the series of solar cells have an N-type front side diffusion regions and the second node being tied to ground when solar cells in the series of solar cells have a P-type front side diffusion regions. ### Claim 7 (depends on 6) The solar energy system of claim 6 wherein the first node is tied to ground by way of a resistor. ### Claim 8 (depends on 6) The solar energy system of claim 6 wherein the inverter is configured to receive a balanced voltage from the solar cell module array and further comprising: a resistor coupling the first node to ground, the resistor having a value configured to unbalance the balanced voltage from the solar cell module array. ### Claim 9 (depends on 6) The solar energy system of claim 6 wherein the inverter is configured to receive a balanced voltage from the solar cell module array and further comprising: a resistor coupling the second node to ground, the resistor having a value configured to unbalance the balanced voltage from the solar cell module array. ### Claim 10 A solar energy system comprising: (a) a plurality of solar cells, each of the solar cells comprising a backside contact solar cell comprising: (i) a front side and a backside, the front side facing the sun during normal operation; (ii) a plurality of metal contacts, each of the metal contacts being coupled to a corresponding collection region of the solar cell; (iii) a dielectric passivation layer formed over a surface of a wafer that faces the sun during normal operation, the dielectric passivation layer being over a front side diffusion region; and (iv) an anti-reflective coating formed over the dielectric passivation layer; (b) a solar cell module array comprising the plurality of solar cells, the solar cell module array having a positive terminal at a positive voltage and a negative terminal at a negative voltage; (c) a ground connection to a frame of a solar cell module in the solar cell module array; (d) an inverter configured to convert direct current generated by the solar cell module array to alternating current to be provided to a power grid; wherein either the positive terminal or the negative terminal of the solar cell module array is tied to ground, the positive terminal of the solar cell module array being tied to ground when the front side diffusion is N-type and the negative terminal of the solar cell module array being tied to ground when the front side diffusion is P-type. ### Claim 11 (depends on 10) The solar cell energy system of claim 10 wherein the inverter is configured to receive a balanced voltage from the solar cell module array and further comprising: a resistance coupling a terminal of the solar cell module array to ground to unbalance the balanced voltage from the solar cell module array such that charge is prevented from leaking from the front side of the solar cells. ### Claim 12 (depends on 11) The solar cell energy system of claim 11 wherein the resistance couples the positive terminal of the solar cell module array to ground. ### Claim 13 (depends on 11) The solar cell energy system of claim 11 wherein the resistance couples the negative terminal of the solar cell module array to ground.