To exploit the beneficial effects of molecular spacers -homogenizing vertical phase distribution and achieving high phase stability, the BDA and PEA-based ternarycomposition quasi-2D HP system is explored. Here, we develop and deploy an active learning algorithm, a Gated-GPBO-based compositional exploration workflow. This allows for iterative discovery of specific compositions realizing target functionalities from a discrete chemical space of the molecular spacers in quasi-2D HPs, where the classical BO cannot achieve it. The quasi-2D HP film, with compositionally tailored by the Gated-GPBO indeed demonstrates the suited bandgaps and high PV performances, exhibiting promising functionalities and manufacturability for tandem PV applications. This work presents an effective experimental data-driven experimental workflow, which realizes bespoke design of optoelectronic functionalities and thus, substantially accelerates materials discovery for sustainable applications. excitation beam. The emission spectra from each film spot were obtained as one 'read cycle' every 15 mins for 96 films. The read cycle was repeated for 10 hours. A PL read sequence is designed for the alternating scan of both the top and bottom surface, obtaining the time-evolved PL spectra from both the top and bottom over time. This results in the actual time interval between the read cycles at each position being 30 min. In Gen5 software, we adjusted the spot size of the excitation beam to be <3 mm in diameter, allowing for confining the excited area in each film. This not only suppresses the emission crosstalk caused from the neighboring films but also excludes undesired characterization of the edge of the film that can have different phase constitutions.