Microcrystalline silicon thin film solar cell and the manufacturing method thereof

Abstract

The present invention relates to a microcrystalline silicon thin film solar cell and the manufacturing method thereof, using which not only the crystallinity of a microcrystalline silicon thin film that is to be formed by the manufacturing method can be controlled and adjusted at will and the defects in the microcrystalline silicon thin film can be fixed, but also the device characteristic degradation due to chamber contamination happening in the manufacturing process, such as plasma enhanced chemical vapor deposition (PECVD), can be eliminated effectively.

What is claimed is: 
     
         1 . A method for manufacturing a microcrystalline silicon thin film solar cell, comprising the steps of:
 using a means of physical vapor deposition (PVD) to form a layer of transparent conducting oxide (TCO) and thus define a pattern on a substrate;   using a means of plasma-enhanced chemical vapor deposition (PECVD) to form a layer of hole-based silicon semiconductor, such as a p-type Si, on the layer of TCO in a first process chamber while enabling the layer of hole-based silicon semiconductor to be used as a hole-based ohmic contact layer;   using a means of plasma-enhanced chemical vapor deposition (PECVD) to form a first layer of intrinsic microcrystalline silicon semiconductor, such as a μ-Si, on the layer of hole-based silicon semiconductor in the first process chamber while enabling the first layer of intrinsic microcrystalline silicon semiconductor to be used as a light absorption layer;   using a means of plasma-enhanced chemical vapor deposition (PECVD) under a condition of high processing pressure and high plasma power to form a second layer of intrinsic microcrystalline silicon semiconductor, such as a μ-Si, on the first layer of intrinsic microcrystalline silicon semiconductor in a second process chamber while enabling the second layer of intrinsic microcrystalline silicon semiconductor to be used also as a light absorption layer;   using a means of plasma-enhanced chemical vapor deposition (PECVD) to form a third layer of intrinsic microcrystalline silicon semiconductor, such as a μ-Si, on the second layer of intrinsic microcrystalline silicon semiconductor in a third process chamber while enabling the second layer of intrinsic microcrystalline silicon semiconductor to be used also as a light absorption layer;   using a means of plasma-enhanced chemical vapor deposition (PECVD) to form a layer of electron-based silicon semiconductor, such as a n-type Si, in a pattern on the third layer of intrinsic microcrystalline silicon semiconductor in the third process chamber while enabling the layer of electron-based silicon semiconductor to be used also as an electron-based ohmic contact layer; and   using a means of physical vapor deposition (PVD) to form a conductive metal layer in a pattern on the layer of electron-based silicon semiconductor while enabling the conductive metal layer to be used as a back electrode, and thereby, achieving a P-I-N structure.   
     
     
         2 . The manufacturing method of  claim 1 , wherein the means of PECVD in the first process chamber is performed using a first plasma source; the first plasma source is capable of providing at least one type of plasma; and the first plasma source is a very high frequency (VHF) plasma source, featured by a frequency selected from the group consisting of: 13.56 MHz, 27.12 MHz, 40 MHz and those higher than 40 MHz. 
     
     
         3 . The manufacturing method of  claim 1 , wherein the means of PECVD in the second process chamber is performed using a second plasma source; the second plasma source is capable of providing at least one type of plasma; and the first plasma source is a very high frequency (VHF) plasma source, featured by a frequency selected from the group consisting of: 13.56 MHz, 27.12 MHz, 40 MHz and those higher than 40 MHz. 
     
     
         4 . The manufacturing method of  claim 1 , wherein the means of PECVD in the third process chamber is performed using a third plasma source; the third plasma source is capable of providing at least one type of plasma; and the first plasma source is a very high frequency (VHF) plasma source, featured by a frequency selected from the group consisting of: 13.56 MHz, 27.12 MHz, 40 MHz and those higher than 40 MHz. 
     
     
         5 . The manufacturing method of  claim 1 , wherein during the forming of the second layer of intrinsic microcrystalline silicon semiconductor on the first layer of intrinsic microcrystalline silicon semiconductor in the second process chamber using the second plasma source, any defect in the first layer of intrinsic microcrystalline silicon semiconductor is remedied and repaired. 
     
     
         6 . The manufacturing method of  claim 1 , wherein the substrate is a substrate selected from the group consisting of: a glass and a flexible thermal-resistant substrate. 
     
     
         7 . The manufacturing method of  claim 1 , wherein the first process chamber is connected to the second process chamber, and the second process chamber is connected to the third process chamber, while the third process chamber is connected to a vacuumed load-lock chamber. 
     
     
         8 . A microcrystalline silicon thin film solar cell, comprising:
 a substrate, being used as the bottom layer of the microcrystalline silicon thin film solar cell;   a layer of transparent conducting oxide (TCO), disposed on the substrate;   a layer of hole-based silicon semiconductor, such as a p-type Si, disposed on the layer of TCO;   a first layer of intrinsic microcrystalline silicon semiconductor, such as a μ-Si, disposed on the layer of hole-based silicon semiconductor;   a second layer of intrinsic microcrystalline silicon semiconductor, such as a μ-Si, disposed on the first layer of intrinsic microcrystalline silicon semiconductor;   a third layer of intrinsic microcrystalline silicon semiconductor, such as a μ-Si, disposed on the second layer of intrinsic microcrystalline silicon semiconductor;   a layer of electron-based silicon semiconductor, such as a n-type Si, disposed on the third layer of intrinsic microcrystalline silicon semiconductor; and   a conductive metal layer, disposed on the layer of electron-based silicon semiconductor.   
     
     
         9 . The microcrystalline silicon thin film solar cell of  claim 8 , wherein the layer of TCO is formed in a pattern on the substrate by a means of physical vapor deposition (PVD). 
     
     
         10 . The microcrystalline silicon thin film solar cell of  claim 8 , wherein the layer of hole-based silicon semiconductor is formed on the layer of TCO in a first process chamber by a means of plasma-enhanced chemical vapor deposition (PECVD), and the layer of hole-based silicon semiconductor is used as a hole-based ohmic contact layer. 
     
     
         11 . The microcrystalline silicon thin film solar cell of  claim 8 , wherein the first layer of intrinsic microcrystalline silicon semiconductor is formed on the layer of hole-based silicon semiconductor in a first process chamber by a means of plasma-enhanced chemical vapor deposition (PECVD), and the first layer of intrinsic microcrystalline silicon semiconductor is used as a light absorption layer. 
     
     
         12 . The microcrystalline silicon thin film solar cell of  claim 8 , wherein the second layer of intrinsic microcrystalline silicon semiconductor is formed on the first layer of intrinsic microcrystalline silicon semiconductor in a second process chamber by a means of plasma-enhanced chemical vapor deposition (PECVD) under a condition of high process pressure and high plasma power, and the second layer of intrinsic microcrystalline silicon semiconductor is used as a light absorption layer. 
     
     
         13 . The microcrystalline silicon thin film solar cell of  claim 8 , wherein the third layer of intrinsic microcrystalline silicon semiconductor is formed on the second layer of intrinsic microcrystalline silicon semiconductor in a third process chamber by a means of plasma-enhanced chemical vapor deposition (PECVD), and the third layer of intrinsic microcrystalline silicon semiconductor is used as a light absorption layer. 
     
     
         14 . The microcrystalline silicon thin film solar cell of  claim 8 , wherein the layer of electron-based silicon semiconductor is formed in a pattern on the third layer of intrinsic microcrystalline silicon semiconductor in the third process chamber by a means of plasma-enhanced chemical vapor deposition (PECVD), and the layer of electron-based silicon semiconductor is used as an electron-based ohmic contact layer. 
     
     
         15 . The microcrystalline silicon thin film solar cell of  claim 8 , wherein the conductive metal layer is formed in a pattern on the layer of electron-based silicon semiconductor by a means of physical vapor deposition (PVD), and the conductive metal layer is used as a back electrode, and thereby, a P-I-N structure is achieved. 
     
     
         16 . The microcrystalline silicon thin film solar cell of  claim 8 , wherein the means of PECVD in the first process chamber is performed using a first plasma source; the first plasma source is capable of providing at least one type of plasma; and the first plasma source is a very high frequency (VHF) plasma source, featured by a frequency selected from the group consisting of: 13.56 MHz, 27.12 MHz, 40 MHz and those higher than 40 MHz. 
     
     
         17 . The microcrystalline silicon thin film solar cell of  claim 8 , wherein the means of PECVD in the second process chamber is performed using a second plasma source; the second plasma source is capable of providing at least one type of plasma; and the second plasma source is a very high frequency (VHF) plasma source, featured by a frequency selected from the group consisting of: 13.56 MHz, 27.12 MHz, 40 MHz and those higher than 40 MHz. 
     
     
         18 . The microcrystalline silicon thin film solar cell of  claim 8 , wherein the means of PECVD in the third process chamber is performed using a third plasma source; the third plasma source is capable of providing at least one type of plasma; and the third plasma source is a very high frequency (VHF) plasma source, featured by a frequency selected from the group consisting of: 13.56 MHz, 27.12 MHz, 40 MHz and those higher than 40 MHz. 
     
     
         19 . The microcrystalline silicon thin film solar cell of  claim 8 , wherein during the forming of the second layer of intrinsic microcrystalline silicon semiconductor on the first layer of intrinsic microcrystalline silicon semiconductor in the second process chamber using the second plasma source, any defect in the first layer of intrinsic microcrystalline silicon semiconductor is remedied and repaired. 
     
     
         20 . The microcrystalline silicon thin film solar cell of  claim 8 , wherein the substrate is a substrate selected from the group consisting of: a glass and a flexible thermal-resistant substrate. 
     
     
         21 . The microcrystalline silicon thin film solar cell of  claim 10 , wherein the first process chamber is connected to the second process chamber, and the second process chamber is connected to the third process chamber, while the third process chamber is connected to a vacuumed load-lock chamber. 
     
     
         22 . The microcrystalline silicon thin film solar cell of  claim 11 , wherein the first process chamber is connected to the second process chamber, and the second process chamber is connected to the third process chamber, while the third process chamber is connected to a vacuumed load-lock chamber. 
     
     
         23 . The microcrystalline silicon thin film solar cell of  claim 12 , wherein the first process chamber is connected to the second process chamber, and the second process chamber is connected to the third process chamber, while the third process chamber is connected to a vacuumed load-lock chamber. 
     
     
         24 . The microcrystalline silicon thin film solar cell of  claim 13 , wherein the first process chamber is connected to the second process chamber, and the second process chamber is connected to the third process chamber, while the third process chamber is connected to a vacuumed load-lock chamber. 
     
     
         25 . The microcrystalline silicon thin film solar cell of  claim 14 , wherein the first process chamber is connected to the second process chamber, and the second process chamber is connected to the third process chamber, while the third process chamber is connected to a vacuumed load-lock chamber.