TY - JOUR
T1 - Effect of localized traps on the anomalous behavior of the transconductance in nanocrystalline TFTs
AU - Estrada, M.
AU - Cerdeira, A.
AU - Resendiz, L.
AU - Iñiguez, B.
AU - Marzal, L. F.
AU - Pallares, J.
N1 - Funding Information:
This work was supported by CONACYT project 34400A in Mexico, by CICYT of the Spanish government under program TIC02-04184 and by the Generalitat de Catalunya in Spain, under program ACI2002-34.
PY - 2005/7
Y1 - 2005/7
N2 - It has been reported that nanocrystalline and microcrystalline devices show an anomalous behavior in the transconductance where several rates of increase of the transconductance with applied gate voltage, not present in amorphous TFTs are observed. In this paper we show that the anomalous effect of the transconductance is observed for an acceptor tail states activation energy similar to the normal values for hydrogenated silicon amorphous devices, (a-Si:H), provided that some conditions are met regarding the density of trapped charge in tail and deep states and the density of free charge in the material, which does not necessarily suggest a behavior in between amorphous and polycrystalline. The effect appears if the density of deep tail states, is smaller (higher) than the typical values in a-Si:H. The localized state distribution present in a nanocrystalline TFT prepared by hot wire deposition technique is estimated by comparison of experimental and simulated transconductance curves. In our case a lower density of deep states is obtained, which corresponds with their better light and bias stability.
AB - It has been reported that nanocrystalline and microcrystalline devices show an anomalous behavior in the transconductance where several rates of increase of the transconductance with applied gate voltage, not present in amorphous TFTs are observed. In this paper we show that the anomalous effect of the transconductance is observed for an acceptor tail states activation energy similar to the normal values for hydrogenated silicon amorphous devices, (a-Si:H), provided that some conditions are met regarding the density of trapped charge in tail and deep states and the density of free charge in the material, which does not necessarily suggest a behavior in between amorphous and polycrystalline. The effect appears if the density of deep tail states, is smaller (higher) than the typical values in a-Si:H. The localized state distribution present in a nanocrystalline TFT prepared by hot wire deposition technique is estimated by comparison of experimental and simulated transconductance curves. In our case a lower density of deep states is obtained, which corresponds with their better light and bias stability.
KW - Amorphous and nanocrystalline silicon
KW - Density of states distribution
KW - TFT
UR - http://www.scopus.com/inward/record.url?scp=20344387816&partnerID=8YFLogxK
U2 - 10.1016/j.microrel.2004.12.005
DO - 10.1016/j.microrel.2004.12.005
M3 - Artículo
SN - 0026-2714
VL - 45
SP - 1161
EP - 1166
JO - Microelectronics Reliability
JF - Microelectronics Reliability
IS - 7-8
ER -