A in situ method is presented for fabricating graded thermal effusivity polymer nanocomposites within a polyvinyl alcohol (PVA) matrix, integrating crosslinking agent glutaraldehyde (GA), graphene oxide (GO), and silver nanoparticles (Ag NPs). Thermal effusivity measurements of resulting materials, including PVA-GO-Ag, PVA-Ag, PVA, PVA-GO, and PVA-GO-Ag-GA, exhibit values of 473.6, 478.8, 495, 638, and 758.4 Ws1/2 m-2 K-1, respectively. Among these, PVA-GO-Ag-GA demonstrates the highest thermal effusivity, suggesting superior heat dissipation capability, complemented by FDTD modeling. The prepared structures exhibit excellent thermal stability enabling them very good candidates for photothermovoltaic applications. Additionally, these nanocomposites boast robust mechanical performance and flexibility, positioning them as promising solutions for industries requiring efficient heat dissipation and mechanical integrity.