Patent ID: 8586151

Claim:
A process for the preparation of photo luminescent nanostructured silicon thin films comprising the steps of: (i) cleaning a substrate and placing it on an anode in a plasma enhanced chemical vapour deposition (PECVD) chamber, (ii) pumping said PECVD chamber to a base pressure of 10 −7 to 10 −8 torr to remove the residual gases, (iii) heating the substrate at a temperature in the range of 180-250° C., (iv) depositing the nanostructured silicon thin film over the substrate by feeding hydrogen diluted silane gas (SiH 4 ) at a rate of 30-50 standard cubic centimeter (sccm) and argon gas at a partial pressure of 30-90%, to said PECVD chamber, for a period of 10-60 minutes, at a chamber pressure of 0.5-10 torr, (v) applying a radio frequency of 13.56 MHz to a cathode in said PECVD chamber, at a power density of 100-1000 mW/cm 2 to achieve a depositing rate of thin silicon film over said substrate in the range of 1-5 A°/sec and (vi) cooling said PECVD chamber to a temperature of 25-30° C., followed by breaking of vacuum by inserting nitrogen gas to obtain the desired nano structured silicon film.