I. First Generation

First generation cells consist of large-area, high quality and single junction devices. First Generation technologies involve high energy and labor inputs which prevent any significant progress in reducing production costs. Single junction silicon devices are approaching the theoretical limiting efficiency of 33%

II. Second Generation

Second generation materials have been developed to address energy requirements and production costs of solar cells. Alternative manufacturing techniques such as vapour deposition, electroplating, and use of Ultrasonic Nozzles are advantageous as they reduce high temperature processing significantly. It is commonly accepted that as manufacturing techniques evolve production costs will be dominated by constituent material requirements.

III. Third Generation

At the early 1990s using  costly  production  processes,  research  laboratories  have  for  many  years  been able  to  produce  highly  efficient  crystalline  silicon  cells  with  efficiencies  up  to  nearly  25 per  cent.  In  these  the  electrical  and  optical  losses  are  minimized.  The source  material  required  here  is  a  highly  pure  polycrystalline  silicon  rod  with  a  mono-crystalline  silicon  seed  at  its  tip  -  but  this  material  is  expensive!