Solar cells are projected to become a leading technology for electricity generation in the forthcoming decades. Improving efficiency and cost-effectiveness by developing high-performance, thin light-absorbing materials offers an attractive strategy to promote the wider use of solar systems. Recent research has extensively examined the structural, electrical, and optical characteristics of the WS 2 /Bi 2 Se 3 van der Waals(vdW) heterostructure using the density functional theory method. This heterostructure material’s electronic characteristics, including the anticipated electronic band structure and state density, as well as those of its component materials WS 2 and Bi 2 Se 3 , have all been investigated. The optical characteristics of the heterostructure WS 2 /Bi 2 Se 3 have been investigated using the Kramers–Kronig (KK) relationship, and the frequency-dependent complex dielectric function has been represented using the Drude model. The WS2/Bi2Se3 heterostructure exhibits superior electromagnetic radiation absorption compared to the individual WS2 or Bi2Se3 monolayers, related to its enhanced absorption coefficient of approximately 106[Formula: see text]cm[Formula: see text] in the visible region. Furthermore, the heterostructure demonstrates considerable absorption in the infrared spectrum. According to the results, WS 2 /Bi 2 Se 3 van der Waals (vdW) heterostructure is a promising material for nano- and opto-electronic devices. The findings indicate robust stability in extreme environmental conditions. Our research indicates that the 2D WS2/Bi2Se3 van der Waals heterostructure is a superior choice for solar device applications and optoelectronic nanodevices.