Most of the part of energy will irreversibly dissipate into the heat and thermoelectric devices are efficient to convert heat into useful electricity. In this work, we focus on fabricating simple, low-cost, eco-friendly and biodegradable metal-carbon-based flexible thermoelectric generators. Thermoelectric devices containing four pairs of p-n legs are developed on two types of paper (coated mechanical paper and Xerox paper) to measure their output characteristics. The device generates output voltage and power of 8.5 mV and 2.1 nW, respectively under a temperature gradient of about 110K. This fast, easy and inexpensive technology could be a suitable method for designing TE devices.