Chinese firm unveils near-record 34.58% efficient hybrid solar cell

Chinese solar module manufacturer Longi has unveiled a new perovskite-silicon tandem solar cell achieving a power conversion efficiency (PCE) of 34.58%, nearing the world record of 34.85% held by the company. The breakthrough centers on an innovative asymmetric self-assembled monolayer (SAM) material called HTL201, which serves as a hole-selective layer. Unlike traditional symmetric carbazole-based SAMs, HTL201’s asymmetric design improves coverage and uniformity on textured silicon substrates and optimizes interfacial energy level alignment. This results in reduced non-radiative recombination losses at the buried interface, a key factor contributing to the cell’s high efficiency. The tandem cell, tested under standard illumination, demonstrated an open-circuit voltage of 2.001 V, a short-circuit current density of 20.64 mA/cm², and a fill factor of 83.79%. The top perovskite layer includes materials such