The Sun is known to be the most powerful source of energy. Solar cells are devices that convert absorbed light into electricity and silicon solar cells are currently the most commonly used technology to do that. However, it has its own drawbacks and other high efficiency solar cell technologies have been developed. Solid-state semiconductor-sensitized solar cells (antimony sulphide solar cells (Sb₂S₃ SCs)) have recently emerged as a promising technology for the further cost reduction of the energy production from the sunlight. Although Sb₂S₃ SCs does not outperform silicon solar cells it has its own advantages, for example simple Sb₂S₃ layer deposition methods, thermal stability and humidity resistance of absorber, etc. [1, 2, 3] However, there are several obstacles that need to be addressed for it to see a widespread use. One of them is the use of expensive charge-transporting semiconductors such as Spiro-OMeTAD, PCPDTBT, etc. [4, 5]. P3HT is also often used as HTM in Sb₂S₃ SCs. However it has parasitic absorption in visible spectral region [6]. Therefore, there is a vigorous search for cheaper and simpler methods for the synthesis of organic semiconductors. According to the literature fluorene chromophores are among the most popular structural building blocks, used for other emerging technologies as organic hole-transporting materials (HTMs)  [7‒9. Furthermore thiophene-based compounds are widely used as HTM’s in Sb₂S₃ SCs [5, 10, 11].

In this work we synthesized fluorene-based compound, containing methoxyphenyl- and thiophene chromophores, that have been obtained by a simple synthetic method. Thermal and photoelectrical properties were investigated, and photovoltaic device was constructed.

The new hole transporting material (V808) was realized under Hartwig-Buchwald amination conditions using commercially available starting materials. New compound bear fluorene fragment with thiophene substituent in 9H position as molecule-core, while 4,4’-dimethoxydiphenylamine was used to build side chromophores. New HTM exhibit good thermal stability, at up to 390 °C. Nevertheless, compound has an amorphous state, which is important for homogenous films forming. The ionization potential (I_p) of target material is  4.95 eV which is suitable for using this compound as HTM in Sb₂S₃ solar cells. The PCE of the most efficient n-i-p Sb₂S₃ device possesing V808 have reached 3.8 % (3.6 % for P3HT). Furthermore, new structure show good transparency, which is higher than P3HT.