Control of alignment regularity and density of nanodots by changing concentration and molecular weight of self-assembling diblock copolymer

We show that nanodots can be regularly aligned on a glass substrate using poly(styrene)-block-poly(2-vinylpyridine) (PS-P2VP) for application in high-density optical media. The alignment regularity and density of the nanodots are determined using the PS-P2VP concentration in solution and the PS-P2VP molecular weight. By optimizing the PS-P2VP concentration in toluene, a distance of 61 nm +/- 8.8% between the nanodots and a data density of 0.20 Tbits/in.(2) are achieved with a molecular weight of 57,500-57,000. With a molecular weight of 25,500-23,500, we demonstrate a dot interval of 46 nm while keeping similar standard deviation and a data density of 0.35 Tbits/in.(2).