Apparatus for Simultaneous Roll-to-Roll Wet Processing of Two Workpieces Disposed Within a Single Chamber

A system for depositing a buffer layer material from a process solution simultaneously onto an exposed surface of a first solar cell absorber layer formed on a first workpiece and onto an exposed surface of a second solar cell absorber layer formed on a second workpiece , the system comprising:

• a chamber to deposit the buffer layer material onto the exposed surfaces of the first and the second absorber layers when both the first and the second absorber layers are simultaneously disposed therein in a face to face configuration, the chamber comprising:
• a first heated wall that heats the first workpiece with the first solar cell absorber layer formed thereon,
• a second heated wall placed substantially across from the first heated wall, thereby forming a gap between the first heated wall and the second heated wall, such that both the first workpiece and the second workpiece simultaneously fit within the gap so that the exposed surface of each of the first and second absorber layers face each other and have a process gap therebetween, wherein the second heated wall heats the second workpiece with the second solar cell absorber layer formed thereon,
• a heating mechanism to heat the first and second heated walls, and thereby heat each of the first and second absorber layers to a temperature sufficient to cause deposition of the buffer layer material onto the exposed surface of each of the first and the second absorber layers from the process solution disposed within the process gap,
• a solution inlet mechanism to flow, at a predetermined rate, the process solution into the process gap and onto the exposed surfaces of the first and second absorber layers , and cause contact of the process solution simultaneously with the exposed surfaces of the first and second absorber layers, and
• a solution outlet to allow removal of used process solution from the process gap at a rate that substantially corresponds to the predetermined rate that the process solution enters the process gap.