I can suggest you PDMS (Syl, I did measurements from RT down to 4K even if you have a thick film (http://www.dowcorning.com/applications/search/products/details.aspx?prod=01064291&type=PROD). PS or PMMA are ok if you prepare a thin film.

Thank you Mannini. Does it make a glass when its in lower temperature ? I wanna use that for optical measurements.

Hi PDMS is the polymer which is transparent and with temperature range from -45 to almost 300 degree celsius. apart from that it is optically transparent. You can form film out of it easily by using two component system called RTV. The manufacturer are Dow Corning, GE, Gelest etc. Another material is poly methyl methacrylate

Yes, is transparent. At RT is soft and you can also easily cut it while at low temp is still transparent , more rigid so glass like. We performed optical measurements (MCD) on it down to 2K.

Thank you very much Mannini . Its really helpful

Thank you very much Mahdiyar , mannini , parimal. I will come with some of results later on. Again its so nice to get this sort of wonderful feed back . Thanks .

Thanks for editing my question and it makes more sense now. thanks again

Pva, pmma

Polymethyl methacrylate, polystyrene, polycarbonate

I used polystyrene cells for low temperature measurements of ethanol solutions. They stay transparent at 77K and ethanol ice doesn't cracked as in quartz but cuvette begin phosphoresce at excitation shorter 380 nm.

Thank you every one. This discussion worth 1000 papers.