Organic–inorganic hybrid perovskite has led to the development of new solar cells with outstanding efficiency. In perovskite solar cells (PSCs), perovskite is sandwiched between a working electrode (fluorine-doped tin oxide) and a counter electrode (gold, Au). In order to transport charges and block opposite charges efficiently, charge transport layers are inserted between perovskite and the electrodes. In particular, a hole transport layer (HTL) is important in the conventional structure because it generally prevents perovskite from exposure to air. Dopants incorporated into the HTL must be harmful to perovskite layer due to their deliquescence and basicity. In addition, hydrophilic HTL cannot prevent the permeation of moisture in air. Therefore, it is necessary to investigate dopant-free and hydrophobic polymeric hole transport materials (HTMs). In this study, a novel polymeric HTM (PTEG) is synthesized by controlling the solubility using a tetraethylene glycol group. PTEG has much better solubility than reference BDT-BT based polymer and suitable energy level alignment with perovskite layer.The planar-PSC employing PTEG exhibits an efficiency of 19.8% without any dopants, which corresponds to the highest value reported to date. In addition, PTEG devices exhibited high efficiency and stability irrespective of the device configuration. This study offers a fundamental strategy for designing and synthesizing various polymeric HTMs.