1. Introduction

Progresses on Organic-Thin-Film-Transistors (OTFTs) made them a promising low-cost alternative to a-Si TFTs [1,2]. Organic devices have many advantages with respect to their silicon counterparts. In fact, organic materials can be inexpensively deposited using many techniques, such as spin-coating or ink-jet printing [3,4]. Those processes require much lower temperatures than those required for silicon deposition, allowing the growth of organic semiconductors over plastic substrates. Plastic substrates, in turn, are flexible, much lighter, more robust to mechanical deformation and cheaper than glass, allowing the integration of organic electronics in many fields. For instance, OTFTs could be employed in RF-IDs, flexible displays, smart textiles, sensors, etc. In many of these applications, a relatively low operating frequency is required, and they are mainly battery or near-field powered. The limited energy/power budget makes complementary logic a desirable choice to cut down power requirements, because static power dissipation is minimized, while dynamic power is relatively small, due to the low operating frequency. Complementary logic also features better noise margins, with respect to nMOS- or pMOS-only logic