Energy harvesters, which are automated systems, can capture and store small amounts of free energy from the environment. These systems typically consist of three stages: a micro-generator source, a power converter, and a storage element. Piezoelectric materials, such as PZT, are often used as transducers to collect mechanical vibrations from the environment due to their high electromechanical coupling factor. However, integrating PZT into silicon has some drawbacks for both the harvesting stage and power management electronics circuit embedding. A recent approach in thermoelectric (TE) energy harvesting is to use abundant, environmentally friendly, and low-cost materials that are compatible with CMOS technologies, such as silicon and silicon-based compound nanostructures for TE thin film devices. Therefore, this review focuses on the most recent advances in characterization, fabrication, and device integration of Si-based thin-film materials for TE energy harvesting applications. Additionally, this work highlights some recent developments in electronic architectures to enhance the efficiency of a complete system.