Heterojunction phototransistors(HPTs)with scaling emitters have a higher optical gain compared to HPTs with normal emitters.However,to quantitatively describe the relationship between the emitter-absorber area ratio(A...Heterojunction phototransistors(HPTs)with scaling emitters have a higher optical gain compared to HPTs with normal emitters.However,to quantitatively describe the relationship between the emitter-absorber area ratio(Ae/Aa)and the performance of HPTs,and to find the optimum value of Ae/Aa for the geometric structure design,we develop an analytical model for the optical gain of HPTs.Moreover,five devices with different Ae/Aa are fabricated to verify the numerical analysis result.As is expected,the measurement result is in good agreement with the analysis model,both of them confirmed that devices with a smaller Ae/Aa exhibit higher optical gain.The device with area ratio of 0.0625 has the highest optical gain,which is two orders of magnitude larger than that of the device with area ratio of 1 at 3 V.However,the dark current of the device with the area ratio of 0.0625 is forty times higher than that of the device with the area ratio of 1.By calculating the signal-to-noise ratios(SNRs)of the devices,the optimal value of Ae/Aa can be obtained to be 0.16.The device with the area ratio of 0.16 has the maximum SNR.This result can be used for future design principles for high performance HPTs.展开更多
Here in this paper,we report a room-temperature operating infrared photodetector based on the interband transition of an In As Sb/Ga Sb quantum well.The interband transition energy of 5-nm thick In As（0.91）Sb（0.09...Here in this paper,we report a room-temperature operating infrared photodetector based on the interband transition of an In As Sb/Ga Sb quantum well.The interband transition energy of 5-nm thick In As（0.91）Sb（0.09） embedded in the Ga Sb barrier is calculated to be 0.53 e V（2.35μm）,which makes the absorption range of In As Sb cover an entire range from short-wavelength infrared to long-wavelength infrared spectrum.The fabricated photodetector exhibits a narrow response range from 2.0μm to 2.3μm with a peak around 2.1μm at 300 K.The peak responsivity is 0.4 A/W under-500-m Vapplied bias voltage,corresponding to a peak quantum efficiency of 23.8%in the case without any anti-reflection coating.At 300 K,the photodetector exhibits a dark current density of 6.05×10^-3A/cm^2 under-400-m V applied bias voltage and 3.25×10^-5A/cm^2 under zero,separately.The peak detectivity is 6.91×10^10cm·Hz^1/2/W under zero bias voltage at 300 K.展开更多
We present a method to extend the operating wavelength of the interband transition quantum well photodetector from an extended short-wavelength infrared region to a middle-wavelength infrared region. In the modified I...We present a method to extend the operating wavelength of the interband transition quantum well photodetector from an extended short-wavelength infrared region to a middle-wavelength infrared region. In the modified In As Sb quantum well, Ga Sb is replaced with Al Sb/Al Ga Sb, the valence band of the barrier material is lowered, the first restricted energy level is higher than the valence band of the barrier material, the energy band structure forms type-II structure. The photocurrent spectrum manifest that the fabricated photodetector exhibits a response range from 1.9 μm to 3.2 μm with two peaks at 2.18 μm and 3.03 μm at 78 K.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11574362,61210014,11374340 and 11474205the Innovative Clean-Energy Research and Application Program of Beijing Municipal Science and Technology Commission under Grant No Z151100003515001the National Key Technology R&D Program of China under Grant No 2016YFB0400302
文摘Heterojunction phototransistors(HPTs)with scaling emitters have a higher optical gain compared to HPTs with normal emitters.However,to quantitatively describe the relationship between the emitter-absorber area ratio(Ae/Aa)and the performance of HPTs,and to find the optimum value of Ae/Aa for the geometric structure design,we develop an analytical model for the optical gain of HPTs.Moreover,five devices with different Ae/Aa are fabricated to verify the numerical analysis result.As is expected,the measurement result is in good agreement with the analysis model,both of them confirmed that devices with a smaller Ae/Aa exhibit higher optical gain.The device with area ratio of 0.0625 has the highest optical gain,which is two orders of magnitude larger than that of the device with area ratio of 1 at 3 V.However,the dark current of the device with the area ratio of 0.0625 is forty times higher than that of the device with the area ratio of 1.By calculating the signal-to-noise ratios(SNRs)of the devices,the optimal value of Ae/Aa can be obtained to be 0.16.The device with the area ratio of 0.16 has the maximum SNR.This result can be used for future design principles for high performance HPTs.
基金Project supported by the National Natural Science Foundation of China(Grant No.11574362)
文摘Here in this paper,we report a room-temperature operating infrared photodetector based on the interband transition of an In As Sb/Ga Sb quantum well.The interband transition energy of 5-nm thick In As（0.91）Sb（0.09） embedded in the Ga Sb barrier is calculated to be 0.53 e V（2.35μm）,which makes the absorption range of In As Sb cover an entire range from short-wavelength infrared to long-wavelength infrared spectrum.The fabricated photodetector exhibits a narrow response range from 2.0μm to 2.3μm with a peak around 2.1μm at 300 K.The peak responsivity is 0.4 A/W under-500-m Vapplied bias voltage,corresponding to a peak quantum efficiency of 23.8%in the case without any anti-reflection coating.At 300 K,the photodetector exhibits a dark current density of 6.05×10^-3A/cm^2 under-400-m V applied bias voltage and 3.25×10^-5A/cm^2 under zero,separately.The peak detectivity is 6.91×10^10cm·Hz^1/2/W under zero bias voltage at 300 K.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11574362,61210014,11374340,and 11474205)the Innovative Clean-Energy Research and Application Program of Beijing Municipal Science and Technology Commission of China(Grant No.Z151100003515001)the National Key Technology R&D Program of China(Grant No.2016YFB0400302)。
文摘We present a method to extend the operating wavelength of the interband transition quantum well photodetector from an extended short-wavelength infrared region to a middle-wavelength infrared region. In the modified In As Sb quantum well, Ga Sb is replaced with Al Sb/Al Ga Sb, the valence band of the barrier material is lowered, the first restricted energy level is higher than the valence band of the barrier material, the energy band structure forms type-II structure. The photocurrent spectrum manifest that the fabricated photodetector exhibits a response range from 1.9 μm to 3.2 μm with two peaks at 2.18 μm and 3.03 μm at 78 K.
