Photovoltaic (PV) systems generate electricity from sunlight using the photovoltaic effect. The electrical efficiency of a PV system in standard test conditions (STC) ranges between 18-24%. This efficiency falls further by 0.4-0.5 %/0C with every degree rise in PV cell temperature above STC. Research shows that containing this cell temperature rise will enhance the electrical efficiency of the system. The photovoltaic thermal (PVT) systems are designed with an active heat dissipation mechanism to curb the cell temperature rise. However, the heat dissipation mechanism does not restrict the cell temperature at a required level, therefore, further advancement is needed in the system to achieve the set temperature levels. The nanofluids and Phase Change Material (PCM) application shows a considerable improvement in the PVT performance. A systematic review of the current state of the art of nanofluids and PCM application in PVT systems is needed to identify the key parameters influencing PVT performance enhancement through this application. Identifying these influential parameters will help studies in future to optimise these applications. It is identified that nanofluid type, volume concentration and flow rate are the imperative parameters of nanofluids application. The magnitude of effect these parameters hold is delineated in this paper. It was noticed that optimum conditions for nanoparticle volume concentration and fluid flow rate are necessary as insufficient or excessive increments in these parameters may restrict the PVT performance. The scope for future studies pertaining to the furtherance of the PVT system is also described in this study.