A semiconductor thin film structure may include a substrate, a buffer layer on the substrate, and a semiconductor layer on the buffer layer, such that the buffer layer is between the semiconductor layer and the substrate. The buffer layer may include a plurality of unit layers. Each unit layer of the plurality of unit layers may include a first layer having first bandgap energy and a first thickness, a second layer having second bandgap energy and a second thickness, and a third layer having third bandgap energy and a third thickness. One layer having a lowest bandgap energy of the first, second, and third layers of the unit layer may be between another two layers of the first, second, and third layers of the unit layer.