A flexible D Flip-Flop (DFF) fabricated in an unipolar n-Type thin-film transistor (TFT) technology is studied and presented. It has two operating modes: low power mode, reaching frequencies up to 16 MHz with only 0.172 mW total power at 3 V supply voltage, and high speed mode, showing over 30 MHz operation at 9 V with 2.59 mW power. To reduce the energy consumption, this enhanced architecture decouples a significant portion of the circuit during part of the operating cycle. To the best of our knowledge, considering comparable thin-film technologies, this DFF provides the highest figure-of-merit (operation frequency/total power), and at high speed mode also the highest operation frequency reported up to date.