One of the major problems in developing countries is dearth of sufficient
energy, which in turn hampers sustainable development. Anatase is one of the
prominent polymorph of Titanium dioxide (TiO2) with great potential for solar
application except for its wide band gap which limits its solar energy utilization to
about 4%. It has fascinated much devotion from researchers owing to its extensive
array of applications coupled with its availability and cost effectiveness. Doping
has been presented as a means to narrow the band gap thereby enhancing its
efficiency for solar application. Electronic and optical properties are presented
here for pure and Nitrogen (N) doped anatase. The study is based on the density
functional theory (DFT) using generalized gradient approximation (GGA) in
addition to Coulomb Interaction (U) as implemented in quantum espresso code
while the optical properties calculation was done with the Yambo code. With the
inclusion of U parameter of 12.5eV, band gap of 3.1eV was obtained which
compared favorably with experimental results. Doping concentration of 3.1% gave
rise to band narrowing while Partial density of state (PDOS) shows that the band
narrowing in anatase is due to the contribution from 2p state of the Nitrogen
dopant. The optical properties calculated revealed that N-doped anatase has optical
crests in the visible light range of electromagnetic spectrum which makes it a
potential material for solar application with higher efficiency than pure anatase.