Cadmium sulfide thin film transistors were demonstrated as the n-type device for use in flexible electronics. CdS thin films were deposited by chemical bath deposition (70 degrees C) on either 100 nm HfO2 or SiO2 as the gate dielectrics. Common gate transistors with channel lengths of 40-100 mu m were fabricated with source and drain aluminum top contacts defined using a shadow mask process. No thermal annealing was performed throughout the device process. X-ray diffraction results clearly show the hexagonal crystalline phase of CdS. The electrical performance of HfO2/CdS-based thin film transistors shows a field effect mobility and threshold voltage of 25 cm(2) V(-1)s(-1) and 2 V, respectively. Improvement in carrier mobility is associated with better nucleation and growth of CdS films deposited on HfO2. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3456551] All rights reserved.