[en] We constructed zero drive load inverters by employing two identical unipolar pentacene thin-film transistors, based on the fabrication technology of organic weak epitaxy growth, which exhibited the features of high gains and large noise margins. Pentacene films were grown on a p-6P inducing layer, which reduced the interface disorder and increased the scale of crystalline domains. The pentacene/p-6P transistors showed high-quality saturation characteristics and the negative shift of threshold voltages, which caused large noise margins and the operation range of full swing. Furthermore, the hole mobility was increased to 1.28 cm² (Vs)⁻¹. As a result, zero drive load inverters exhibited a large gain of up to 30, compared with the gains of only four based on single pentacene transistors. We also discuss the dependence of large gains and device performance. These results demonstrated the fabrication technology of organic weak epitaxy growth were promising and advantageous for achieving high performance organic inverters and logic circuits. (paper)