Indoor Energy Harvesting: Exploring novel materials and methods for indoor energy harvesting
World population is increasing and so is the global power demand. The current population is 7.8 billion and the global power demand is ~ 18 TW. By 2050, the projected population is ~ 9 billion and power demand will rise to ~ 30 TW. UN’s sustainable developmental goal is ‘Universal access to affordable, reliable and sustainable modern energy services by 2030’. Also, the International panel on climate change (IPCC) demand ‘virtually full decarbonisation of the power sector by ~ 2050’. To realise these targets, ‘energy security’ or secure use of our limited energy resources are essential.
Buildings are the largest consumers of primary energy, consuming around 40 % of total energy. Also, the building sector accounts for more than 40 % of global CO2 emission to the atmosphere. In ‘Energy Harvesting Research Group’ we aim to develop novel materials and devices to ‘recycle’ energy inside the buildings and use it to power the innumerable number of sensors in the ‘Internet of Things (IoT)- the key technology to smart, energy-efficient buildings.
We explore the energy harvesting properties of halide perovskites (with the general formula, ABX3, where A is the organic or inorganic cation, B is the divalent cation and X the anion) to realise our aim. These semiconducting materials are solution-processable, earth-abundant, possess high absorption coefficient in the visible range (10^5-10^6 cm^-1), high charge carrier mobility (1-10 cm^2/Vs) and have tunable bandgap (1.1 -3.3 eV) and thus integrate all the requirements for a cost-effective energy harvester.
Hybrid perovskite crystal structure (example)
Recently we have demonstrated a low temperature (~100 °C) solution – processed and ultrathin (~6 nm) NiO nanoparticle thin films as an efficient hole extraction layers (HEL) for indoor photovoltaics with a power conversion efficiency (PCE) of 23.0% for CH3NH3PbI2.9Cl0.1 p-i-n solar cells under compact fluorescent lighting. Compared to the perovskite solar cells fabricated on PEDOT:PSS HEL, better shelf-life stability is observed for perovskite solar cells fabricated on NiO HEL. The full article can be read here; Full article