Laminate structures for high temperature photovoltaic applications, and methods relating thereto

A CIGS laminate structure comprising:

• a) a metal foil having a thickness from 5 to 100 microns,
• b) a polyimide dielectric layer having a top surface and a bottom surface, the bottom surface being in direct contact with a surface of the metal foil, the polyimide dielectric layer having a thickness from 8 to 100 microns and comprising a polyimide derived from:
• i. an aromatic diahydride, the aromatic dianhydride being an aromatic rigid rod dianhydride and optionally, an aromatic non rigid rod dianhydride, where at least 50 mole percent of the aromatic dianhydride is an aromatic rigid rod dianhydride and the remainder, if any, is an aromatic non rigid rod dianhydride;
• and ii. an aromatic diamine, the aromatic diamine being an aromatic rigid rod diamine and optionally, an aromatic non rigid rod diamine, where at least 50 mole percent of the aromatic diamine is an aromatic rigid rod diamine and the remainder, if any, is an aromatic non rigid rod diamine, wherein:
• i) the aromatic rigid rod diamine is selected from a group consisting of 1,4-diaminobenzene (PPD), 4,4′-diaminobiphenyl, 2,2′-bis(trifluoromethyl)benzidene (TFMB), 1,4-naphthalenediamine, 1,5-naphthalenediamine and mixtures thereof;
• ii.) the non rigid rod aromatic diamine is selected from a group consisting of 3,4′-diaminodiphenyl ether (3,4′-ODA), 4,4′-diaminodiphenyl ether (4,4′-ODA), 1,3-diaminobenzene (MPD), 4,4′-diaminodiphenyl sulfide, 9,9′-bis(4-amino)fluorene, and mixtures there;
• iii) the aromatic rigid rod dianhydride is selected from a group consisting of pyromellitic dianhydride (PMDA), 3,3′,4,4′-biphenyl tetracarboxylic dianhydride (BPDA), and mixtures thereof;
• and
• iv) the non rigid rod aromatic dianhydride is selected from a group consisting of:
• 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA);
• 4,4′-oxydiphthalic anhydride (ODPA), 3,3′,4,4′-diphenyl sulfone tetracarboxylic dianhydride (DSDA), 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and mixtures thereof,
• to provide a polyimide having a Tg greater than 300° C. and to provide a polyimide layer having an isothermal weight loss of less than 1% under inert conditions at 500° C. over 30 minutes and an in-plane CTE less than 25 ppm/° C.,
• c) a bottom electrode formed directly on the polyimide dielectric layer top surface, whereby the polyimide layer is between the metal foil and the bottom electrode, and
• d) a CIGS layer formed directly on the bottom electrode, whereby the bottom electrode is between the CIGS layer and the polyimide dielectric layer.