Abstract: A polymer, which is a composition of a battery, is polymerized by a polymeric precursor, and the polymeric precursor includes at least two or at least three monomers. Each of the monomers is a lactone, a lactone cyclic ester or a carbonate ester. The polymer includes a polyester, and the polyester is a straight chain.

Abstract: A solar cell includes a substrate, an emitter layer, a first thin oxide layer, a first doped silicon layer, a second thin oxide layer, and a second doped silicon layer. The substrate has a first side and a second side opposite to each other. The emitter layer is disposed on the first side of the substrate and includes a first conductivity type of dopant. The first thin oxide layer is disposed on the emitter layer. The first doped silicon layer is disposed on the first thin oxide layer and includes the first conductivity type of dopant. The second thin oxide layer is disposed on the second side of the substrate. The second doped silicon layer is disposed on the second thin oxide layer and includes a second conductivity type of dopant. A method for manufacturing a solar cell is also provided herein.