# Infrared Photovoltaic–Battery Hybrid Systems Enabled by Colloidal Quantum Dots

## TL;DR

This paper reviews how colloidal quantum dots can improve low-cost infrared energy systems by combining solar harvesting and battery storage.

## Contribution

The paper provides a comprehensive review of colloidal quantum dots for near-infrared photovoltaic-battery systems and identifies future research directions.

## Key findings

- Colloidal quantum dots offer cost-effective near-infrared light absorption for photovoltaic systems.
- Current PV/B systems using silicon and III-V semiconductors are less efficient in the infrared range.
- The review synthesizes progress and gaps in NIR CQD-based PV/B systems.

## Abstract

Photovoltaic‐battery (PV/B) hybrid energy systems have gained global attention due to the depletion of fossil fuels and environmental concerns. PV systems play a crucial role in sustainable power generation as they produce clean, environmentally‐friendly energy directly from sunlight. Compared to the first‐generation silicon PVs, which are ineffective for wavelengths beyond 1100 nm, and the high‐cost second‐generation III‐V semiconductors, Colloidal quantum dots (CQDs) stand out as a key material in the latest generation of PVs. They offer the advantage of absorbing light in the near‐infrared (NIR) range at a significantly lower cost. Current PV/B systems often integrate silicon PVs with lithium‐ion batteries or direct photobatteries and have demonstrated reliable performance. Although substantial academic work has focused on NIR CQD‐based PVs and batteries, research directions in NIR PV/B hybrid systems remain somewhat disorganized and uneven. This review focus on: (i) providing a detailed analysis of CQDs, including their chemical and physical properties and their applications in NIR PV cells, and (ii) summarizing literature on past and current NIR CQDPVs and batteries that could be used in PV/B systems, synthesizing diverse sources of information. This article seeks to offer new insights and identify potential future research directions for professionals in the field.

Photovoltaic–battery (PV/B) hybrid systems are key for sustainable energy but face cost and efficiency limits. Colloidal quantum dots (CQDs) enable low‐cost near‐infrared light harvesting, surpassing silicon and III–V PVs. This review analyzes CQD properties, their roles in NIR PVs and batteries, and synthesizes current research to highlight progress and future directions in NIR PV/B hybrid systems.