Making perovskite solar cells as durable as silicon ones

Solar cells (cells) based on compounds of the type known as perovskites (because they have the basic structure of the mineral from which they take their name) are much cheaper to manufacture than silicon solar cells, and also have greater flexibility and other advantages. Since the creation of the first ones in the last decade, their energy conversion efficiency has increased dramatically, reaching values ​​above 25%. However, while much effort has been devoted to increasing power conversion efficiency, very little has been devoted to solving the fundamental problems that prevent such materials from being widely used in commercial applications…

Compared to silicon, perovskites can degrade rapidly under environmental conditions to which silicon in conventional solar cells is typically exposed. Exposure to heat and moisture causes damage to perovskites and negatively affects the performance of solar cells made from them.

Solving these stability problems is the main challenge that perovskites now face to replace silicon or to “power” it through a tandem architecture, and occupy the place that conventional silicon solar cells currently occupy in the panorama. business of photovoltaic energy.

Now, a key breakthrough in this regard has been achieved by an international team consisting of, among others, Philippe Holzhey and Henry Snaith, both from the University of Oxford in the UK, and Udo Bach, from Monash University in Australia as well as the Center of Excellence in Exciton Science (Exciton Science), under the Australian Research Council (ARC, for its acronym in English).

Philippe Holzhey. (Photo: Exciton Science)

This team has demonstrated a new way to create stable perovskite solar cells, with fewer defects and potentially capable of finally rivaling the durability of silicon.

By eliminating the dimethyl sulfoxide solvent and introducing dimethylammonium chloride as a crystallization agent, the researchers were able to better control the intermediate stages of the perovskite crystallization process, resulting in higher quality thin films with fewer defects and greater stability.

Next, large groups of up to 138 sample devices underwent a rigorous accelerated aging process and testing at high temperatures and real ambient conditions.

The perovskite formamidinium-cesium solar cells created using the new synthesis process significantly outperformed normal ones and demonstrated resistance to degradation by heat, moisture, and light.

This is a big step toward the goal of perovskite solar cells that are as durable as silicon ones and cost less.

Holzhey and his colleagues report the technical details of their breakthrough in the academic journal Nature Materials, under the title “Intermediate-phase engineering via dimethylammonium cation additive for stable perovskite solar cells.” (Font: NCYT by Amazings)