Despite the tremendously rapid development of perovskite photovoltaics (PV) in terms of power conversion efficiency (PCE) the stability of such devices typically still does not fulfill the requirements for commercialization of this technology. Up to date, PV devices with carbon-based back-electrodes (CBEs) have demonstrated the longest operational stability, surpassing several IEC 61215 standards [1]. Moreover, recently we reported that such modules could withstand requirements of the IEC hot-spot test (evaluating the stability of PV devices against reverse-bias degradation),[2] which is one of the most crucial hurdles not only for perovskite PV, but even for such well-established PV technology as c-Si. [3] Thus, devices with CBEs represent a promising method for up-scalable manufacturing of stable and low-cost perovskite PV devices.[4,5]

However, besides cost and stability, we must also consider greenhouse gas (GHG) emissions coming from PV manufacturing, which are projected to grow beyond national emissions of countries like France or Germany in the next 10 years.[6] Although the production of perovskite PV with CBEs has the potential to reach the lowest CO₂-footprint limit possible for large scale PV applications,[4] one of the methods to reduce the GHG emissions of PV industry further is the development of effective recycling strategies, where perovskite materials offer unique advantage of liquid processing.

Up to now, only studies on the recyclability and life-cycle-assessments of non-encapsulated devices have been demonstrated. To show that perovskite PV devices with CBEs can not only be stable but also recyclable, we manufactured such solar cells and modules, encapsulated with thermoplastic polyolefin and polyisobutylene edge-seal, which provide sufficient protection against moisture, passing the IEC damp-heat test. [7] Through life-cycle assessment, we show that most of the negative environmental impact comes from the layer deposition, rather than the environmental footprint of material itself, making the re-use of as many layers as possible the most preferable option. We demonstrate an effective mechanochemical method to remove the edge-seal and encapsulant, as well as degraded perovskite and CBEs, leaving metal oxide layers intact making them available for re-use. Our novel recycling method of such devices results in minimal performance loss, which helps to reduce the negative environmental impact of such devices (global warming potential in kg CO₂-eq./kW_p) by > 40%. Such strong reduction in the global-warming potential of perovskite solar modules with CBEs qualifies them as truly sustainable PV technology meeting all requirements for its introduction to the PV market.