Semi-transparent perovskite solar cells (ST-PSCs) are highly attractive to improve the efficiency of commercial silicon (Si) photovoltaic cells and modules in tandem architectures. In this work, efficient 1.6 electron volt  band gap ST-PSCs with an inverted configuration were prepared after optimizing the stack and decreasing the optical and electrical losses, resulting in 20.5% cell efficiency and +29.5% perovskite/c-Si four-terminal tandem cell efficiency. A dual passivation approach was applied to reduce non-radiative recombination losses. First, a series of alkali halides were introduced as additive to the perovskite bulk. Secondly, large organic cations were introduced at the perovskite/electron transport layer (ETL) interface. As a result, compared to 18.1% stabilized power conversion efficiency (PCE) for the reference ST-PSC, a remarkable gain in stabilized PCE of 20.5% was demonstrated. We also highlight that encapsulated devices exhibited the similar or even better photovoltaic performance after keeping them in dark and Nitrogen shelf life condition for more than one year. The ST-PSCs retained 95% of their initial stabilized PCE after 1600h aging at 85°C in a nitrogen atmosphere. The light soak stability test is currently on going and the results are expected after the submission of this abstract. Besides high efficiency, and stability, the development of ST-PSCs for tandem application requires a high near-infrared (NIR)  transparency. The optimized ST-PSCs exhibited NIR transmittance of about 92% (800 nm to 1200 nm) which was accomplished by improving transparent conductive oxide ( TCO ) electrodes quality and tuning the thickness of component layers in the top perovskite cells and using anti-reflective coating layers [1]. For four-terminal tandem application, the ST-PSC (0.09 cm2) with optimized NIR transparency was coupled with a larger Panasonic silicon heterojunction (SHJ) bottom cell  leading to a calculated [2] +29.5% stabilized PCE, with more than 5% absolute efficiency gain with respect to the standalone bottom Si cell. Even more importantly, manufacturing technology of small area devices [3-5] have been transferred to scalable processes, potentially for large volume production. As a result, NIR semi-transparent modules with an aperture area of 100 cm2 were fabricated using the slot-die, evaporation, sputtering and spatial atomic layer deposition (sALD) procedures. The unencapsulated module exhibits a power conversion efficiency of 16.0% on aperture area and 17.3% on active area leading to +25% area matched perovskite/c-Si four-terminal tandem module efficiency. These results can be important step towards the commercialization of perovskite/Si tandem solar cells.