NOVELTY - Forming a stacked p-i-n solar cell involves: providing a single plasma-enhanced chemical vapor deposition (PECVD) processing chamber (100) configured to deposit a p-doped, i-, and an n-doped layers; placing substrate (101) having surface area of greater than or equal to 1 m2 within the the chamber; forming p-doped layer upon the substrate; forming i-layer overlying p-doped layer; and forming n-doped layer overlying i-layer, such that all the layers are formed in the same processing chamber.    USE - For forming a stacked p-i-n solar cell (claimed).    ADVANTAGE - The use of a single plasma-enhanced chemical vapor deposition (PECVD) chamber for the production of stacked solar cell; reduces the cost per power generation by increasing the conversion efficiencies (CE), by making efficient use of the apparatus used to fabricate the solar cells; and provides higher throughput with less equipment to drive down the fabrication costs, while at the same time maximizes the CE of the solar cell; as compared to the prior art processes. The method is a single chamber process that forms thin film p-i-n solar cells and still achieves collection efficiencies of at least 9-12%. These relatively high collection efficiencies (compared with previous collection efficiencies for thin film solar cells) can be achieved using a single chamber manufacturing process by altering the overall chemical and structural composition of the p-doped and/or n-doped silicon-containing layer from that previously known art, to provide a silicon-carbide containing composition and structure within the p-doped layer, to improve CE of the solar cell. This is achieved by selection of particular materials and processing conditions to form the thin cell layers. The ability to form the thin film solar cells in a single chamber increases efficiency of production, so that the cost of manufacture balanced against the output of the solar cell has demonstrated that a single chamber production method is acceptable. The single chamber process allows for a throughput increase in a range of 6-35% over the prior art three chamber process, depending on the number of chambers in a cluster processing system. The lowest throughput increase of 6% of the single chamber process over the three chamber process is for a 7 chamber cluster system for a single junction p-i-n process. The highest throughput increase of 35% of the single chamber process over the three chamber process is for a 5 chamber cluster processing system, which provides a two junction p-i-n process (a tandem cell process), where at least the bottom cell of the two cells is fabricated using micro-crystalline silicon layers.    DETAILED DESCRIPTION - Method for forming a stacked p-i-n solar cell involves: providing a single plasma-enhanced chemical vapor deposition (PECVD) (100) processing chamber configured to deposit a p-doped, i-, and an n-doped layers; placing substrate (101) having surface area of greater than or equal to 1 m2 within the the chamber; forming p-doped layer upon the substrate; forming i-layer overlying p-doped layer; and forming n-doped layer overlying i-layer, such that all the layers are formed in the same processing chamber. The method further involves: forming second p-doped layer overlying n-doped layer, second i-layer overlying second p-doped layer; and forming second n-doped layer overlying surface of second i-layer. Processing steps for the top cell of stacked solar cell are carried out in PECVD processing chamber configured to deposit amorphous (a)-silicon-comprising p-doped layer, a-silicon-comprising i-layer, and dual n-doped layer, where top portion of dual n-doped layer comprises a-silicon, and a bottom portion of the dual n-doped layer comprises multicrystalline (mc)-silicon. Processing steps for bottom cell of the stacked solar cell are carried out in a PECVD processing chamber configured to deposit mc-silicon-comprising p-doped layer, mc-silicon-comprising i-layer, and a-silicon-comprising n-doped layer; or is configured to deposit either a-comprising silicon layer or a mc-comprising silicon layer. The substrate comprises optically transparent electrode layer upon which the p-layer is deposited. After placing the substrate in a chamber, the substrate is heated to greater than or equal to 150 degrees C. In the forming of the p-doped layer as a silicon-comprising layer doped with a carbon-comprising boron compound upon substrate, the process chamber wall surfaces adjacent substrate are held at greater than or equal to 50 degrees C lower than the substrate temperature. An INDEPENDENT CLAIM is included for a cluster processing system comprising: at least one single processing chamber which is configured to deposit a p-doped layer, an i-layer, and an n-doped layer (preferably either a-silicon-comprising layer, or mc-silicon-comprising layer).    DESCRIPTION OF DRAWING(S) - The figure shows the PECVD processing chamber.    PECVD processing chamber (100)    Substrate (101)    Walls (102)    Process volume (106)    Gas source (120)    radio-frequency power (122)    Substrate support. (130)