High-energy, short-pulse laser-driven proton-boron pB fusion has garnered increasing interest due to its neutronless nature and potential for clean energy production. In our study, two experimental campaigns were conducted using the LFEX PW laser facility to investigate the impact of complex target geometries including spheres, cylinders, and wedges on α-particle yield. Our findings reveal that spherical targets produce an α-particle yield approximately one order of magnitude higher than flat targets of the same composition, with a notable shift in α-particle energy towards higher values. Additionally, we successfully implemented a novel method for unambiguous α-particle detection using CR-39 detector within a Thomson Parabola spectrometer. Particle-in-cell (PIC) simulations with the Smilei code further elucidate the influence of self-generated magnetic fields on particle dynamics, highlighting the intricate relationship between target confinement and fusion efficiency. These results provide valuable insights into optimizing target designs for enhancing energy conversion in laser pB fusion