Systems for charging solar cell layers

Abstract

Systems and methods of the present invention can be used to charge a charge-holding layer (such as a passivation layer and/or antireflective layer) of a solar cell with a positive or negative charge as desired. The charge-holding layer(s) of such a cell can include any suitable dielectric material capable of holding either a negative or a positive charge, and can be charged at any suitable point during manufacture of the cell, including during or after deposition of the passivation layer(s).

What is claimed is: 
     
         1 . A system comprising:
 a chamber including:
 (a) a gas inlet configured to inject a gas into the chamber; 
 (b) a plasma-generating electrode; 
 (c) a radio-frequency power supply electrically coupled to the plasma-generating electrode, the radio-frequency power supply configured to apply an alternating current to the plasma-generating electrode to generate a plasma by ionizing the gas, wherein photons from the plasma have an energy level of at least about 3.1 eV; 
 (d) a charging electrode configured to receive a provided solar cell such that the solar cell and charging electrode are in electrical communication, wherein the solar cell includes: 
 an emitter; 
 a base; 
 a first passivation layer adjacent the emitter; and 
 a second passivation layer adjacent the base; and 
 (e) a direct current power supply electrically coupled to the charging electrode, whereby when the direct current power supply applies a direct current voltage pulse to the charging electrode for a predetermined period of time, one or more of the first passivation layer and the second passivation layer is charged to a predetermined polarity. 
   
     
     
         2 . The system of  claim 1 , further comprising:
 a switch electrically coupled to the charging electrode, wherein the direct current power supply is electrically coupled to the charging electrode via the switch;   wherein the switch is configured to alternately enable and disable the electrical coupling between:
 the charging electrode and electrical ground; and 
 the direct-current power supply and the charging electrode. 
   
     
     
         3 . The system of  claim 1 , wherein the predetermined period of time is between about 1 microsecond and 10 seconds. 
     
     
         4 . The system of  claim 1 , wherein the direct current pulse has a voltage of between about 10 volts and about 5,000 volts. 
     
     
         5 . The system of  claim 1 , wherein the direct current pulse is positively biased. 
     
     
         6 . The system of  claim 1 , wherein the direct current pulse is negatively biased. 
     
     
         7 . The system of  claim 1 , wherein the gas includes an inert gas. 
     
     
         8 . The system of  claim 1 , Wherein the inert gas includes one or more of argon, nitrogen, and helium. 
     
     
         9 . The system of  claim 1 , wherein the gas inlet is configured to inject, into the chamber, silane (SiH4) and ammonia (NH3), wherein the radio-frequency power supply is further configured to apply an alternating current to the plasma-generating electrode to generate another plasma using the SiH4 and NH3. 
     
     
         10 . The system of  claim 1 , whereby application of the direct current pulse to the charging electrode generates an electric field between the charging electrode and the plasma-generating electrode.