TY - JOUR
T1 - Generation of hot carrier population in colloidal silicon quantum dots for high-efficiency photovoltaics
AU - Zhang, Pengfei
AU - Feng, Yu
AU - Wen, Xiaoming
AU - Cao, Wenkai
AU - Anthony, Rebecca
AU - Kortshagen, Uwe
AU - Conibeer, Gavin
AU - Huang, Shujuan
PY - 2016/2
Y1 - 2016/2
N2 - Hot carrier generation in silicon (Si) quantum dots (QDs) is studied with power dependent continuous wave photoluminescence (CWPL) spectroscopy. By taking sub-band gap absorption into account, a modified Maxwell-Boltzmann-form equation was employed to achieve accurate theoretical fitting to the CWPL spectra of the Si QDs. As a fitting parameter, the excited carrier temperature was calculated. A steady-state carrier population was revealed with a temperature 500 K above room temperature under illumination equivalent to one standard sun (100 mW/cm2). In addition, sice the carrier temperature increased with the power of illumination, a state filling effect is proposed as a reasonable cause for the elevated carrier temperature by comparative study of the CWPL spectra of Si QDs with three different sizes. These Si QDs show great potential for one of the steps towards a practical hot carrier solar cell (HCSC) device as high carrier temperatures can be achieved by state filling under mild illumination.
AB - Hot carrier generation in silicon (Si) quantum dots (QDs) is studied with power dependent continuous wave photoluminescence (CWPL) spectroscopy. By taking sub-band gap absorption into account, a modified Maxwell-Boltzmann-form equation was employed to achieve accurate theoretical fitting to the CWPL spectra of the Si QDs. As a fitting parameter, the excited carrier temperature was calculated. A steady-state carrier population was revealed with a temperature 500 K above room temperature under illumination equivalent to one standard sun (100 mW/cm2). In addition, sice the carrier temperature increased with the power of illumination, a state filling effect is proposed as a reasonable cause for the elevated carrier temperature by comparative study of the CWPL spectra of Si QDs with three different sizes. These Si QDs show great potential for one of the steps towards a practical hot carrier solar cell (HCSC) device as high carrier temperatures can be achieved by state filling under mild illumination.
KW - Hot carrier solar cell
KW - Silicon quantum dots
KW - Photoluminescence
KW - State filling
UR - http://www.scopus.com/inward/record.url?scp=84948783439&partnerID=8YFLogxK
U2 - 10.1016/j.solmat.2015.11.002
DO - 10.1016/j.solmat.2015.11.002
M3 - Article
AN - SCOPUS:84948783439
SN - 0927-0248
VL - 145
SP - 391
EP - 396
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
IS - Part 3
ER -