A polyolefin based hot melt adhesive composition having improved heat resistance includes a blend of about 5% to 50% by weight of a glassy semicrystalline poly-alpha-olefin polymer, about 5% to 70% by weight of a soft or rubbery polymer, about 5% to 65% by weight of a tackifier, about 0% to 3% by weight of a stabilizer and optionally a wax andor plasticizer. The device includes a substrate, and a plurality of nanofingers. All embodiments of the invention comprise a folded bit lines scheme, either in adjacent bit lines or in segment-to-segment folded bit lines. The buffer layer has a maximal concentration of the first conductive type impurity therein of approximately 5\xd71015 cm\u22123 or less, and the collector layer has a maximal concentration of the second conductive type impurity therein of approximately 1\xd71017 cm\u22123 or more.