Optical Studies of Electronic States, Vibrations            and Relaxation Processes in Amorphous Systems
{'Code': '03070003', 'Directorate': {'Abbreviation': 'MPS', 'LongName': 'Direct For Mathematical & Physical Scien'}, 'Division': {'Abbreviation': 'DMR', 'LongName': 'Division Of Materials Research'}}
{'SignBlockName': 'Carol A. Savory-Heflin', 'PO_EMAI': None, 'PO_PHON': None}
Studies will be made of electron states in the gap (in the bulk                 and at interfaces), carrier transport and recombinatiion                        processes in a-Si:H and related materials (undoped and variously                doped films,and multilayer structures).  CW and time-resolved                   photomodulation spectroscopy in a broad spectral range and time                 domain from femtoseconds to seconds will be used.  Photogenerated               carriers will be followed as they dribble down in energy through                band states, different traps in the gap, and eventually                         recombine.  In the femtosecond range, the pump and probe                        technique for studying energy, momentum and coherence relaxations               of excited electronic states will be employed.  In the picosecond               range, a new technique, optical time-of-flight method will be                   used, for studying the carrier transport in a-Si:H at very short                times, using the a-Si:H/a-SiNx:H multilayer structures.  In the                 ranges fromnanoseconds up, studies will be made of the evolution                of the carrier densities both in energy and time from which                     carrier transport between specific states in the gap and carrier                recombination can be obtained.  Another new method, cw                          photomodulation spectroscopy of vibrations, for identifying the                 bonding structures with which a certain electronic state in the                 gap is correlated will be used.
{'FirstName': 'Jan', 'LastName': 'Tauc', 'PI_MID_INIT': None, 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Jan Tauc', 'EmailAddress': None, 'NSF_ID': '000104313', 'StartDate': '11/15/1987', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'Brown University', 'CityName': 'PROVIDENCE', 'ZipCode': '029129100', 'PhoneNumber': '4018632777', 'StreetAddress': '1 PROSPECT ST', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'Rhode Island', 'StateCode': 'RI', 'CONGRESSDISTRICT': '01', 'CONGRESS_DISTRICT_ORG': 'RI01', 'ORG_UEI_NUM': 'E3FDXZ6TBHW3', 'ORG_LGL_BUS_NAME': 'BROWN UNIVERSITY', 'ORG_PRNT_UEI_NUM': None}
{'Name': None, 'CityName': None, 'StateCode': None, 'ZipCode': None, 'StreetAddress': None, 'CountryCode': None, 'CountryName': None, 'StateName': None, 'CountryFlag': None, 'CONGRESSDISTRICT': None, 'CONGRESS_DISTRICT_PERF': '""'}
{'Code': '1761', 'Text': 'SOLID STATE PHYSICS'}
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1987&All=true', 'xml': '8706289.xml'}