TY - JOUR
T1 - Anomalous band gap behavior in mixed Sn and Pb perovskites enables broadening of absorption spectrum in solar cells
AU - Hao, Feng
AU - Stoumpos, Constantinos C.
AU - Chang, Robert P.H.
AU - Kanatzidis, Mercouri G.
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/6/4
Y1 - 2014/6/4
N2 - Perovskite-based solar cells have recently been catapulted to the cutting edge of thin-film photovoltaic research and development because of their promise for high-power conversion efficiencies and ease of fabrication. Two types of generic perovskites compounds have been used in cell fabrication: either Pb- or Sn-based. Here, we describe the performance of perovskite solar cells based on alloyed perovskite solid solutions of methylammonium tin iodide and its lead analogue (CH3NH3Sn1-xPbxI 3). We exploit the fact that, the energy band gaps of the mixed Pb/Sn compounds do not follow a linear trend (the Vegard's law) in between these two extremes of 1.55 and 1.35 eV, respectively, but have narrower bandgap (<1.3 eV), thus extending the light absorption into the near-infrared (∼1,050 nm). A series of solution-processed solid-state photovoltaic devices using a mixture of organic spiro-OMeTAD/lithium bis(trifluoromethylsulfonyl)imide/pyridinium additives as hole transport layer were fabricated and studied as a function of Sn to Pb ratio. Our results show that CH3NH3Sn 0.5Pb0.5I3 has the broadest light absorption and highest short-circuit photocurrent density ∼20 mA cm-2 (obtained under simulated full sunlight of 100 mW cm-2).
AB - Perovskite-based solar cells have recently been catapulted to the cutting edge of thin-film photovoltaic research and development because of their promise for high-power conversion efficiencies and ease of fabrication. Two types of generic perovskites compounds have been used in cell fabrication: either Pb- or Sn-based. Here, we describe the performance of perovskite solar cells based on alloyed perovskite solid solutions of methylammonium tin iodide and its lead analogue (CH3NH3Sn1-xPbxI 3). We exploit the fact that, the energy band gaps of the mixed Pb/Sn compounds do not follow a linear trend (the Vegard's law) in between these two extremes of 1.55 and 1.35 eV, respectively, but have narrower bandgap (<1.3 eV), thus extending the light absorption into the near-infrared (∼1,050 nm). A series of solution-processed solid-state photovoltaic devices using a mixture of organic spiro-OMeTAD/lithium bis(trifluoromethylsulfonyl)imide/pyridinium additives as hole transport layer were fabricated and studied as a function of Sn to Pb ratio. Our results show that CH3NH3Sn 0.5Pb0.5I3 has the broadest light absorption and highest short-circuit photocurrent density ∼20 mA cm-2 (obtained under simulated full sunlight of 100 mW cm-2).
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U2 - 10.1021/ja5033259
DO - 10.1021/ja5033259
M3 - Article
AN - SCOPUS:84901937010
VL - 136
SP - 8094
EP - 8099
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 22
ER -