Renewable and non-polluting energy is one of the biggest challenges of modern society; hence the new energy sources which would provide simple and cost-effective solutions are necessary. Solar cells are an important alternative energy source, which takes an increasing role in the current distribution of energy production, and is a full-fledged replacement for fossil energy. Unlike other forms of energy, solar energy is a completely ecological energy source and it does not cause side effects. Furthermore, solar energy can be differentiated – it can be used both locally for a small device operation and broadly for residential house electricity and heat supply or significant size industrial solar plants with several megawatts of power. Organic thin films with semiconductor properties nowadays are widely studied as their use in organic electronics or photonics is very promising, including solar cell development. Organic materials have several significant advantages: dimensions of electronic components can be very small, as one molecule acts as an electronic element; manufacturing process has significantly less impact on the environment because the required temperature to create organic solar cells can be several times reduced compared to silicon based solar cells; cheap and easy recycling; possibility to create flexible devices. Thus, organic materials provide opportunities to expand the use of solar energy. Material selection is one of the prerequisites to develop organic solar cells. The knowledge of material properties and energy structure can play a crucial role in development of organic solar cells. In this work indandione containing compounds with different functional groups attached have been investigated. Added groups allowed improving the energy parameters and photovoltaic properties compared with other previously known indandione compounds. An attached tri-phenyl group gives the possibility to make organic solar cells from the solution. The traditional method for making thin films – thermal deposition in vacuum – is costly and requires large amounts of energy. Thin films fabrication from solution saves energy and raw materials, particularly when printing or "roll-to-roll" method is applied. Solar cell fabrication from solution is becoming more and more popular, but now it is possible mostly using polymers. Fabrication from solution using low molecular weight compounds instead of polymers is more cost-effective because repeatability of the synthesis of low molecular weight compounds is significantly higher and at the same time recycling process is much easier than that of polymers.